Why Might a Bank That Has Purchased a Cap Also

Why might a bank that has purchased a cap also wish to also sell a floor?

A) By themselves, caps are ineffective at limiting changes in a bank's cost of funds in a desirable way.
B) Regulators require one to be used with the other.
C) Selling a floor reduces the cost of buying the cap.
D) Dealers won't sell a cap without also dealing with the floor to limit their own risk.
E) It is not a complete hedge without both positions.