The scenario that poses the greatest risk to an organization from a privacy perspective is that the organization lacks a hardware disposal policy. A hardware disposal policy is a policy that defines how the organization should dispose of or destroy hardware devices that contain or process personal data, such as laptops, servers, hard drives, USBs, etc. A hardware disposal policy should ensure that personal data is securely erased or overwritten before the hardware device is discarded, recycled, donated, or sold. A hardware disposal policy should also comply with the applicable privacy regulations and standards that govern data retention and destruction. By lacking a hardware disposal policy, the organization exposes personal data to potential threats, such as theft, loss, or unauthorized access, use, disclosure, or transfer. Reference: : CDPSE Review Manual (Digital Version), page 123

The best practice to protect data privacy when disposing removable backup media is B. Data sanitization.
A comprehensive explanation is:
Data sanitization is the process of permanently and irreversibly erasing or destroying the data on a storage device or media, such as a hard drive, a USB drive, a CD/DVD, etc. Data sanitization ensures that the data cannot be recovered or reconstructed by any means, even by using specialized software or hardware tools. Data sanitization is also known as data wiping, data erasure, data destruction, or data disposal.
Data sanitization is the best practice to protect data privacy when disposing removable backup media because it prevents unauthorized access, disclosure, theft, or misuse of the sensitive or confidential data that may be stored on the medi a. Data sanitization also helps to comply with the legal and regulatory requirements and standards for data protection and privacy, such as the General Data Protection Regulation (GDPR), the Health Insurance Portability and Accountability Act (HIPAA), the Payment Card Industry Data Security Standard (PCI DSS), etc.
There are different methods and techniques for data sanitization, depending on the type and format of the storage device or media. Some of the common methods are:
Overwriting: Overwriting replaces the existing data on the device or media with random or meaningless data, such as zeros, ones, or patterns. Overwriting can be done multiple times to increase the level of security and assurance. Overwriting is suitable for magnetic media, such as hard disk drives (HDDs) or tapes.
Degaussing: Degaussing exposes the device or media to a strong magnetic field that disrupts and destroys the magnetic structure and alignment of the data. Degaussing renders the device or media unusable and unreadable. Degaussing is suitable for magnetic media, such as hard disk drives (HDDs) or tapes.
Physical Destruction: Physical destruction involves applying physical force or damage to the device or media that breaks it into small pieces or shreds it. Physical destruction can be done by using mechanical tools, such as shredders, crushers, drills, hammers, etc., or by using thermal methods, such as incineration, melting, etc. Physical destruction is suitable for any type of media, such as hard disk drives (HDDs), solid state drives (SSDs), USB drives, CDs/DVDs, etc.
Data encryption (A) is not a good practice to protect data privacy when disposing removable backup media because it does not erase or destroy the data on the media. Data encryption only transforms the data into an unreadable format that can only be accessed with a key or a password. However, if the key or password is lost, stolen, compromised, or guessed by an attacker, the data can still be decrypted and exposed. Data encryption is more suitable for protecting data in transit or at rest, but not for disposing data.
Data scrambling is not a good practice to protect data privacy when disposing removable backup media because it does not erase or destroy the data on the media. Data scrambling only rearranges the order of the bits or bytes of the data to make it appear random or meaningless. However, if the algorithm or pattern of scrambling is known or discovered by an attacker, the data can still be unscrambled and restored. Data scrambling is more suitable for obfuscating data for testing or debugging purposes, but not for disposing data.
Data masking (D) is not a good practice to protect data privacy when disposing removable backup media because it does not erase or destroy the data on the media. Data masking only replaces some parts of the data with fictitious or anonymized values to hide its true identity or meaning. However, if the original data is still stored somewhere else or if the masking technique is weak or reversible by an attacker, the data can still be unmasked and revealed. Data masking is more suitable for protecting data in use or in analysis, but not for disposing data.
Reference:
What Is Data Sanitization?1
How to securely erase hard drives (HDDs) and solid state drives (SSDs)2 Secure Data Disposal & Destruction: 6 Methods to Follow3

A privacy impact assessment (PIA) is a systematic process to identify and evaluate the potential privacy impacts of a system, project, program or initiative that involves the collection, use, disclosure or retention of personal data. A PIA should be done first when planning a new implementation for tracking consumer web browser activity, as it would help to ensure that privacy risks are identified and mitigated before the implementation is executed. A PIA would also help to ensure compliance with privacy principles, laws and regulations, and alignment with consumer expectations and preferences. The other options are not as important as conducting a PIA when planning a new implementation for tracking consumer web browser activity. Seeking approval from regulatory authorities may be required or advisable for some types of personal data or data processing activities, but it may not be necessary or sufficient for tracking consumer web browser activity, depending on the context and jurisdiction. Obtaining consent from the organization's clients may be required or advisable for some types of personal data or data processing activities, but it may not be necessary or sufficient for tracking consumer web browser activity, depending on the context and jurisdiction. Reviewing and updating the cookie policy may be required or advisable for some types of personal data or data processing activities, but it may not be necessary or sufficient for tracking consumer web browser activity, depending on the context and jurisdiction1, p. 67 Reference: 1: CDPSE Review Manual (Digital Version)

Following an established privacy framework is the most important step when developing an organizational data privacy program because it provides a structured and consistent approach to identify, assess, and manage privacy risks and compliance obligations. A privacy framework can also help to align the privacy program with the organization's strategic goals, values, and culture, as well as to communicate and demonstrate the privacy program's effectiveness to internal and external stakeholders. Some examples of established privacy frameworks are the NIST Privacy Framework, the ISO/IEC 27701:2019, and the AICPA Privacy Maturity Model.
Reference:
NIST Privacy Framework: A Tool for Improving Privacy through Enterprise Risk Management, NIST ISO/IEC 27701:2019 Security techniques - Extension to ISO/IEC 27001 and ISO/IEC 27002 for privacy information management - Requirements and guidelines, ISO Privacy Maturity Model, AICPA

The best way to address the concern that data collected by a third-party vendor and provided back to the organization may not be protected according to the organization's privacy notice is to validate contract compliance. This means that the organization should verify that the third-party vendor is adhering to the terms and conditions of the contract, which should include clauses on data protection, privacy, and security. The contract should also specify the obligations and responsibilities of both parties regarding data collection, processing, storage, transfer, retention, and disposal. By validating contract compliance, the organization can ensure that the third-party vendor is following the same privacy standards and practices as the organization.
Reference:
ISACA, CDPSE Review Manual 2021, Chapter 2: Privacy Governance, Section 2.3: Third-Party Management, p. 51-52.
ISACA, Data Privacy Audit/Assurance Program, Control Objective 8: Third-Party Management, p. 14-151