You are the audit senior assigned to the audit of Fix-IT Ltd, a motor vehicle spares company. You obtain an understanding of the ordering function within the revenue and receipts cycle at Fix-IT Ltd. All orders are captured by the debtors' clerk who will input the order on the revenue system by creating an internal sales order and capturing the order details. Which one of the following programme controls should be implemented to ensure that the order quantity is accurate before processing the order?

a.

Alpha numeric check

b.

Limit check

c.

Validation check

d.

Mandatory fields check