In Which of the Following Cases Is a Bank Obliged

In which of the following cases is a bank obliged to file a Currency Transaction Report (CTR) with the Internal Revenue Service?

A) The bank receives instructions from a customer to certify an ordinary check worth $10,000 issued in a foreigner's name.
B) The bank receives an ordinary check worth $13,000 payable to a customer's checking account.
C) A customer deposits $20,000 through a cashier's check in his or her checking account.
D) A customer issues stop-payment instructions on a check worth $15,000 issued to a payee.