An internal auditor discovers that a vendor had submitted invoices and was paid for services not rendered. Which of the following controls is most…

Comprehensive and Detailed Step-by-Step Explanation:

Reference to IIA Standards:

Standard 2130 - Control: Internal audit must assess whether controls ensure compliance and prevent

fraud.

Reasoning:

Option A directly addresses the root cause: payment for unrendered services. Requiring

acknowledgment of receipt ensures only valid invoices are paid.

Option B (observing invoice input) ensures data entry accuracy but does not address fraud.

Option C (verifying amounts) ensures correct payments for legitimate invoices but does not prevent

unauthorized payments.

Best Practice:

Verifying acknowledgment of services before payment is a preventive control, reducing fraud risk.