Correct answer is D.
The public health advocates are concerned that patients are exposed to advertisements about prescription drugs, and may pursue these drugs even though the drugs may not be clinically appropriate. It is argued that, because physicians must prescribe the drugs in question, patient pursuit of these prescription drugs is irrelevant. However, patients who pursue and request particular prescription drugs may be able to encourage or induce a physician to prescribe drugs that he or she might not have prescribed otherwise.in the absence of such encouragement.
There maybe some confusion b/w C & D, but C can be rejected because it does not address the public health advocates' concerns.