Detailed Explanation:

Rationale for Correct Answer:Fraudulent schemes involving returns and allowances can be detected by analyzing accounts for unusually high transactions in these categories. This is a common red flag for concealment of theft or manipulation of sales.

Analysis of Incorrect Options:

A. Allowances by vendors – Too narrow, not a standard analytic test.

B. Disposals of allowances than reorders – Not a recognized search method.

D. None of the above – Incorrect, since option C is valid.

Key Concept:Returns and allowances analysis for fraud detection.