The Nurse Enters the Postoperative Client's Room and Finds the Client

The nurse enters the postoperative client's room and finds the client perspiring with fists clenched.As the nurse administers routine medications and provides care,the client is pleasant and cooperative.Which action by the nurse is the most appropriate?

A) Documenting "no complaints of pain offered" and assessing that the client is comfortable
B) Asking the client if pain is being experienced
C) Informing the client that he looks uncomfortable and asking him to describe his pain
D) Instructing the client to use the call bell if he experiences pain