Comprehensive and Detailed Step-by-Step Explanation: Awalk-through of job functionsprovides direct evidence thatseparation of duties (SoD)is implemented effectively. It involves observing employees as they perform tasks to confirm that no single person has excessive privileges. * Walk-through of Job Functions (Correct Answer - D) * Confirms that duties are appropriately divided in real-world operations. * Helps verify whether security policies and controls are enforced. * Example:An auditor observes that the same person cannot create and approve financial transactions. * Review of Personnel Files (Incorrect - A) * Personnel files contain job details but do not confirm how duties are performed. * Analysis of Documented Job Descriptions (Incorrect - B) * Job descriptions may be outdated or inaccurate. * Review of Organizational Chart (Incorrect - C) * Shows reporting relationships but does not confirm SoD implementation. References: * ISACA CISA Review Manual * COBIT 2019: Risk Management and Governance * ISO 27001: Segregation of Duties Control