Choice "C" is correct. When confirming the total accounts receivable balance, it is beneficial to include a client-prepared statement of account that shows the details of the account balances so that the confirmation recipients can more easily verify the receivable balance.
Choice "d" is incorrect. The client's shipping documents would not generally be helpful to allow a respondent to be able to confirm an existing balance.
Choice "b" is incorrect. Listing client payments that had already been recorded would generally not be relevant in confirming unpaid invoices.
Choice "a" is incorrect. The customer's purchase orders would not generally be helpful to allow a respondent to be able to confirm an existing balance.