Which of the following controls is most likely to help ensure that all credit revenue transactions of an entity are recorded?

a. The billing department supervisor sends a copy of each approved sales order to the credit department for comparison to the customer's au- thorized credit limit and current account balance.

b. The accounting department supervisor independently reconciles the accounts receivable subsidiary ledger to the accounts receivable con- trol account each month.

c. The accounting department supervisor controls the mailing of monthly statements to customers and investigates any differences re- Ported by customers.

d. The billing department supervisor matches prenumbered shipping documents with entries in the sales journal.L-987