Hussein Got a Call Yesterday from First Bank, the Company

Hussein got a call yesterday from First Bank, the company that issued his credit card inquiring about an $105.00 charge made in Buenos Aires, Argentina. Upon learning that Hussein was in Detroit and had not made this purchase, the bank quickly took steps to cancel the card and issue a new one. Given the circumstances that Hussein's credit card number had an illegal transaction, he may also want to

A) check his computer's firewall to make sure it's working.
B) cancel his account and eliminate credit cards from his life.
C) change his passwords and store them in a password manager.
D) diversify his spending habits by using one of several credit cards when making purchases.