An auditor is performing a preliminary assessment of the client's internal control over purchases. Which of the following would be considered improper segregation of duties over purchase transactions for a large client?

A) The purchasing department prepares a pre-numbered requisition and obtains all required approvals.

B) The receiving department has the initial custody of goods from the vendor.

C) The accounting department posts the purchase transaction to the general ledger

D) The accounts payable department prepares a pre-numbered voucher and enters data into the accounts payable subsidiary ledger.