The Nurse Witnesses the Patient's Signature on a Consent Form

The nurse witnesses the patient's signature on a consent form to participate in a physician's research study. After the physician leaves the room, the patient tells the nurse, "I don't really want to participate, but I'm afraid my doctor will be upset with me if I say no." To advocate for the patient, which nursing action is most appropriate?

A) Tell the patient the physician will not be upset if she declines to participate.
B) Inform the physician about why the patient agreed to participate.
C) Explain the importance of the research study to the patient.
D) Ask the patient to tell the nurse whether or not any action should be taken.