It is illegal to advertise prescription medications in Hedland except directly to physicians, either by mail or in medical journals.  A proposed law would allow general advertising of prescription medications.  Opponents object that the general population lacks the specialized knowledge to evaluate such advertisements and might ask their physicians for inappropriate medications.  But since physicians have the final say as to whether to prescribe a medication for a patient, inappropriate prescriptions would not become more common.

Which of the following would it be most useful to establish in order to evaluate the argument?

(A) Whether advertising for prescription medications might alert patients to the existence of effective treatments for minor ailments that they had previously thought to be untreatable

(B) Whether some people might go to a physician for no reason other than to ask for a particular medication they have seen advertised

(C) Whether the proposed law requires prescription-medication advertisements directed to the general public to provide the same information as do advertisements directed to physicians

(D) Whether advertisements for prescription medications are currently an important source of information about newly available medications for physicians

(E) Whether physicians would give in to a patient's demand for a prescription medication chosen by the patient when the one originally prescribed by the physician fails to perform as desired

answer is E.

想问一下，答案D 为什么不对啊？