During the Cardiac Auscultation the Nurse Hears a Sound Occurring

During the cardiac auscultation the nurse hears a sound occurring immediately after S₂ at the second left intercostal space.To further assess this sound,what should the nurse do?

A) Have the patient turn to the left side while the nurse listens with the bell.
B) Ask the patient to hold his breath while the nurse listens again.
C) No further assessment is needed because the nurse knows it is an S3.
D) Watch the patient's respirations while listening for effect on the sound.