A) The primary objective in the audit of accounts payable is to ascertain the correctness of the amount and goods recorded as accounts payable. Fraud could be done by creating a false account payable or an account payable could be recorded with the wrong amount or name. The audit of accounts payable ensures the safety of the firm and the creditors.

B) A sampling of the accounts payable data is done as if the firm has a lot of account payables then the audit could take a very long time to get completed hence sampling theory is followed. The sample created needs to be reconsidered if there is any negative finding during the audit. The sampling methods are systematic selection, monetary unit sampling, haphazard selection, and block selection method.

Firstly, The sample is selected based on random selection and monetary unit sampling. The account payables are categorized based on the monetary unit sampling method and then, the random selection sampling method is followed for the auditing purposes. If any discrepancies are found out then systematic sampling trough block selection method is followed to decrease the audit risk.