Phil Has a Credit-Card from Credible Cards,Inc

Multiple Choice

Phil has a credit-card from Credible Cards,Inc. Credible Cards decides to make changes to Phil's credit-card terms. Credible Cards

A) must give Phil at least thirty days' notice before changing the terms.
B) must give Phil at least forty-five days' notice before changing the terms.
C) need not give Phil any notice before changing the terms.
D) is not allowed to change the terms.