Which of the following represents the best method for confirming that vendor invoices were for authorized purchases?

a. Vouching vendor invoices to payments made

b. Sorting invoices by purchase orders and comparing for successive duplicate invoices

c. Comparing a random sample of vendor invoices to purchase orders

d. Sorting payments by invoice to detect successive duplicate invoices

Which of the following would a supervising internal auditor most likely discuss during an exit conference with the client?

a. Whether the audit engagement was completed on budget

b. The risk of incorrect acceptance of the samples tested by the auditor

c. The authority of the auditor to hold copies of confidential files

d. Feedback on the audit staffs performance during the engagement