In a small internal audit function, a single auditor is responsible for conducting the entire...

According to the CIA study materials, in small audit functions where one person conducts the engagement, a checklist ensures that tasks are documented and provides a record of completion. This creates a reliable audit trail and supports supervisory review (per Standard 2330 – Documenting Information).

Option A does not apply since only one auditor is involved.

Option B is incorrect because checklists are not primarily for business representatives.

Option C is incorrect: prior audit results would be found in past reports, not a checklist.

Therefore, the primary benefit in this scenario is retention of an audit trail (Option D).