In each of the following situations, indicate the nature or type of non sampling risk that caused the error to occur.

a. Letters were sent to accounts payable vendors for each amount recorded on the books. Later, a large amount of unrecorded accounts payable was discovered.

b. The auditor asked the custodian of the petty cash fund to sign a statement certifying that all disbursements from the fund were properly accounted for and documented. Later, it was discovered that large amounts of unauthorized expenditures had been made.

c. The auditor receives a letter from a bank official stating that the amount of cash on the client’s books is on deposit at the end of the fiscal year. Later, it was discovered that the cash account was restricted.