Office Max Inc. is an office supplies retailer. When a customer places an order, an invoice is issued, and payment is received at the time of the order. A copy of the invoice is then sent to the warehouse to arrange for shipment on the date requested by the customer. Once shipped, a shipping slip is created and the shipment is recorded in a shipping log$.$ The shipping slip is then stapled to the invoice and provided to the accounting department to record the sale.

Which one of the following procedures BEST addresses completeness of sales at Office Max?

Question $3$ options:

$1)$

Select the last $10$ sales for the year from the sales ledger and vouch them to the shipping documents and invoice.

$2)$

Select a sample of sales transactions from the sales ledger and vouch to the corresponding invoice and shipping slip.

$3)$

Select a sample of invoices and trace to sales ledger.

$4)$

Select a sample of shipments from the shipping log and trace to the sales ledger.