Which of the following procedures involves audit sampling?

Select one:

a.

Vouching accounts payable balances to supplier invoices for 20 randomly selectedcreditors.

b.Review of the aged accounts receivable ledger.

c.

Vouching accounts receivable to sales invoices for all balances that have been outstandingfor more than 60 days.

d.Calculation of inventory turnover for selected items of inventory.