A Patient Has a Morphine Sulfate Patient Controlled Analgesia (PCA)to

A patient has a morphine sulfate patient controlled analgesia (PCA) to control postoperative pain.When the nurse enters the room,the patient complains of pain.The nurse's first response is which of the following?

A) Stop the infusion.
B) Call the physician or health care provider immediately.
C) Ask the patient to describe the pain.
D) Speak to the patient in a calming tone to reduce anxiety.