A Client Who Reports an Allergy to Penicillin Is Ordered

A client who reports an allergy to penicillin is ordered to receive cephalexin (Keflex) . The correct action for the nurse is to:

A) administer the medication as ordered with additional fluids.
B) administer the medication and carefully observe for allergic reaction.
C) call the physician to change the order because of the allergy history.
D) administer another antibiotic after consulting the pharmacist.