Correct Answer: CTo determine how an employee could steal and cash checks sent to the organization, the most efficient method would involve examining the endorsements and banks of deposit on customers' canceled checks. This can reveal any discrepancies such as unauthorized endorsements or deposits into suspicious accounts, directly leading to the identification of fraudulent activity and possibly the perpetrator. Confirming accounts receivable or payable would not provide this specific detailed forensic information. While flowcharting and analyzing key controls can help identify potential weaknesses, it may not efficiently reveal the specific fraudulent actions or the perpetrator in this case.