Verification of hash totals is a detective control. A detective control is a control that aims to identify and report errors or irregularities that have already occurred. Verification of hash totals is a technique that compares the hash values of data before and after transmission or processing to detect any changes or corruption. The other options are examples of other types of controls, such as programmed edit checks (preventive), backup procedures (recovery), and use of pass cards (preventive). References: CISA Review Manual, 27th Edition, page 223

Data classification is the process of organizing data into categories based on its sensitivity, value, and risk to the organization. Data classification helps to ensure that data is protected according to its importance and regulatory requirements. Data classification also enables data owners to make informed decisions about data access, retention, and disposal.
To implement a data classification program, it is most important to formalize data ownership. Data owners are the individuals or business units that have the authority and responsibility for the data they create or use. Data owners should be involved in defining the data classification levels, assigning the appropriate classification to their data, and ensuring that the data is handled according to the established policies and procedures. Data owners should also review and update the data classification periodically or when there are changes in the data or its usage.
The other options are not as important as formalizing data ownership when implementing a data classification program. Understanding the data classification levels is necessary, but it is not sufficient without identifying the data owners who will apply them. Developing a privacy policy is a good practice, but it is not specific to data classification. Planning for secure storage capacity is a technical consideration, but it does not address the business and legal aspects of data classification.
References:
ISACA, CISA Review Manual, 27th Edition, 2020, page 247
Data Classification: What It Is and Howto Implement It

Comprehensive and Detailed Explanation:
When verifying the integrity of a bit-for-bit copy of digital evidence, hashing algorithms are used. The primary factors in selecting a hashing algorithm are speed and collision resistance.
MD5 (Message Digest 5): While not cryptographically secure for all modern applications due to collision vulnerabilities, it is very fast and still acceptable in forensic integrity verification where speed is critical and the probability of collision is negligible for one-time checks.
SHA-1 / SHA-2: Provide stronger cryptographic assurance but are slower than MD5. They are preferred for long-term integrity assurance but not when processing speed is the top priority.
AES (Advanced Encryption Standard): AES is an encryption algorithm, not a hashing algorithm, and therefore is not appropriate for integrity verification.
# ISACA Reference: CISA Review Manual 27th Edition, Domain 5 (Protection of Information Assets), section on cryptographic controls for evidence integrity.