Choice "A" is correct. Accounting for unused prenumbered purchase orders and receiving reports is an effective control, but it would not typically be performed in the vouchers payable department.
Choice "c" is incorrect. Reconciling the vendor invoice with the related receiving report is typically performed by a vouchers payable clerk.
Choice "b" is incorrect. The vouchers payable department is responsible for approving vouchers for payment.
Choice "d" is incorrect. Indicating the asset and expense accounts to be debited is not an internal control procedure.
