An internal auditor has completed an assurance engagement.

In the context of an assurance engagement, the auditor determines the scope of the engagement during the planning phase, which includes identifying the specific areas to be reviewed. In this case, if the engagement included a review of the security and privacy of payroll records, it means that during the planning phase, the auditor identified this area as part of the engagement scope. This step is crucial to ensure that the engagement objectives are met and that all relevant risks and controls are evaluated.

The IIA Standards: Standard 2200 – Engagement Planning: "Internal auditors must develop and document a plan for each engagement, including the engagement’s objectives, scope, timing, and resource allocations."

The IIA Practice Guide: "Engagement Planning: Establishing Objectives and Scope": Emphasizes the importance of defining the scope during the planning phase.