A dual$-$purpose test involves a test of controls and a test of details. Which of the following is a dual$-$purpose test?

$$ The auditor considered the client's method for estimating bad debts and evaluated estimates included in the allowance for

doubtful accounts.

$$ The auditor examined a sample of paid vouchers to verify that the voucher was properly approved and to agree the

supporting documentation to the amount paid.

$$ The auditor examined a sample of approved voucher packages to verify the required presence of a purchase order, receiving

report, and vendor invoice and the signature of the supervisor.

$$ The auditor examined a sample of inventory purchase transactions to determine if they were properly recorded and

classified.