Comprehensive and Detailed Explanation:

The most important step in a privacy audit is to ensure that all risks associated with PII handling are identified. This requires analyzing the entire PII data life cycle—from collection, processing, storage, and transfer to retention and destruction.

Option A: Reviewing data management controls is part of the audit but is narrower than life cycle coverage.

Option B: Privacy training is necessary, but training alone doesn’t ensure compliance.

Option C: Reviewing third-party agreements is important but only covers outsourced risks.

Option D: Provides comprehensive coverage of privacy risks across all stages.

???? ISACA Reference: CISA Review Manual 27th Edition, Domain 5, section on data privacy, data life cycle, and PII risks.