Which of the following procedures would provide the most reliable audit evidence? a. Inquiries of the client’s internal audit staff. b. Inspection of prenumbered client purchase orders filed in the...

Which of the following procedures would provide the most reliable audit evidence?
a. Inquiries of the client’s internal audit staff.
b. Inspection of prenumbered client purchase orders filed in the vouchers payable department.
c. Inspection of vendor sales invoices received from client personnel.
d. Inspection of bank statements obtained directly from the client’s financial institution.