31.Which of the following questions would most likely be included in an internal control questionnaire concerning the completeness assertion for purchases?

a.Is an authorized purchase order required before the receiving department can accept a shipment of the vouchers payable department can record a voucher?

b.Are purchase requisitions pre-numbered and independently matched with vendor invoice?

c.Is the unpaid voucher file periodically reconciled with inventory records by an employee who does not have access o purchase requisitions

d.Are purchase orders, receiving reports, and vouchers pre-numbered and periodically accounted for?