Explanation
Requiring independent audits of the providers' data privacy controls is the best way to ensure third-party providers that process an organization's personal data are addressed as part of the data privacy strategy.
Independent audits can verify that the providers are complying with the applicable data privacy laws and regulations, as well as the organization's own policies and standards. Independent audits can also identify any gaps or weaknesses in the providers' data privacy controls and recommend corrective actions or improvements.
References:
What Is Your Privacy and Data Protection Strategy? - ISACA
Why data privacy and third-party risk teams need to work together - OneTrust

Explanation
A data processor that handles personal data for multiple customers has decided to migrate its data warehouse to a third-party provider. The processor is obligated to seek approval from all in-scope data controllers prior to implementation. A data controller is an entity that determines the purposes and means of processing personal data. A data processor is an entity that processes personal data on behalf of a data controller. A third-party provider is an entity that provides services or resources to another entity, such as a cloud service provider or a hosting provider.
According to various privacy laws and regulations, such as the GDPR or the CCPA, a data processor must obtain explicit consent from the data controller before engaging another processor or transferring personal data to a third country or an international organization. The consent must specify the identity of the other processor or the third country or international organization, as well as the safeguards and guarantees for the protection of personal data. The consent must also be documented in a written contract or other legal act that binds the processor to respect the same obligations as the controller.
Seeking approval from all in-scope data controllers can help ensure that the processor complies with its contractual and legal obligations, respects the rights and preferences of the data subjects, and maintains transparency and accountability for its processing activities.
Obtaining assurance that data subject requests will continue to be handled appropriately, implementing comparable industry-standard data encryption in the new data warehouse, or ensuring data retention periods are documented are also good practices for a data processor that migrates its data warehouse to a third-party provider, but they are not obligations prior to implementation. Rather, they are requirements or recommendations during or after implementation.
Obtaining assurance that data subject requests will continue to be handled appropriately is a requirement for a data processor that processes personal data on behalf of a data controller. Data subject requests are requests made by individuals to exercise their rights regarding their personal data, such as access, rectification, erasure, restriction, portability, or objection. A data processor must assist the data controller in fulfilling these requests within a reasonable time frame and without undue delay.
Implementing comparable industry-standard data encryption in the new data warehouse is a recommendation for a data processor that transfers personal data to another system or location. Data encryption is a process of transforming data into an unreadable form using a secret key or algorithm. Data encryption can help protect the confidentiality, integrity, and availability of personal data by preventing unauthorized access, disclosure, or modification.
Ensuring data retention periods are documented is a requirement for a data processor that stores personal data on behalf of a data controller. Data retention periods are the durations for which personal data are kept before they are deleted or anonymized. Data retention periods must be determined by the purpose and necessity of processing personal data and must comply with legal and regulatory obligations.
References: Data warehouse migration tips: preparation and discovery - Google Cloud, Plan a data warehouse migration - Cloud Adoption Framework, Migrating your traditional data warehouse platform to BigQuery ...

Explanation
Encryption is a security practice that transforms data into an unreadable format using a secret key or algorithm. Encryption protects the confidentiality and integrity of data, especially when they are transferred using email or other communication channels. Encryption ensures that only authorized parties can access and use the data, while unauthorized parties cannot decipher or modify the data without the key or algorithm.
Encryption also helps to comply with data protection laws and regulations, such as the General Data Protection Regulation (GDPR) or the California Consumer Privacy Act (CCPA), which require data controllers and processors to implement appropriate technical and organizational measures to safeguard personal data.
Centrally managed encryption is a type of encryption that is implemented and controlled by a central authority or system, such as an organization or a service provider. Centrally managed encryption has the following advantages over end user-managed encryption, private cloud storage space, or password-protected .zip files, for reducing the risk of compromise when transferring personal information using email:
It can enforce consistent and standardized encryption policies and procedures across the organization or the service, such as the encryption standards, algorithms, keys, modes, and formats.
It can automate the encryption and decryption processes for the users, without requiring them to perform any manual actions or install any software or plug-ins on their devices.
It can monitor and audit the encryption activities and incidents, and provide visibility and accountability for the data protection and compliance status.
It can reduce the human errors or negligence that may compromise the encryption security, such as losing or sharing the keys, forgetting or reusing the passwords, or sending the data to the wrong recipients.
References:
Encryption in the Hands of End Users - ISACA, section 2: "A key goal of encryption is to protect the file even when direct access is possible or the transfer is intercepted." The Complexity Conundrum: Simplifying Data Security - ISACA, section 3: "Centrally managed encryption solutions can help enterprises overcome these challenges by providing a unified platform for encrypting data across different environments and applications." Email Encryption: What You Need to Know - Lifewire, section 1: "Email encryption is a way of protecting your email messages from being read by anyone other than the intended recipients."

Explanation
Pseudonymization is a technique that replaces direct identifiers in a data set with pseudonyms or artificial identifiers that do not reveal the identity of the data subjects. Pseudonymization reduces the linkability of the data set with the original identity of the data subjects and thus enhances the privacy and security of the data.
However, pseudonymization is not irreversible and the original identity can be re-established if the pseudonym or key is compromised. Therefore, it is important to keep the identifier separate and distinct from the data it protects and to apply additional security measures to safeguard the identifier. The other options are not relevant to pseudonymization1, p. 74-75 References: 1: CDPSE Review Manual (Digital Version)