Comprehensive and Detailed Step-by-Step Explanation:

Reference to Internal Control Assessment:

Standard 2130 - Control: Internal auditors must evaluate the adequacy and effectiveness of controls in mitigating risks.

COSO Framework: Proper segregation of duties is essential for preventing unauthorized transactions and fraud.

Reasoning:

Option B is correct because the lack of management review and approval for creating vendors indicates a control weakness, as it creates opportunities for unauthorized vendors or fraud. The auditor should investigate whether mitigating controls exist (e.g., periodic review of vendor lists) or recommend redesigning the process to include managerial oversight.

Option A dismisses the observation without considering its impact on control adequacy. Prompt payment alone does not address risks related to unauthorized vendors.

Option C incorrectly assumes the observation reflects adequate controls, which is not the case given the lack of management approval.

Actionable Next Steps:

Document the observation as a control deficiency.

Perform additional testing to identify whether compensating controls mitigate the risk or recommend enhancements to strengthen controls.