In countries in which new life-sustaining drugs cannot be patented, such drugs are sold at widely affordable prices; those same drugs, where patented, command premium prices because the patents shield patent-holding manufacturers from competitors. These facts show that future access to new life-sustaining drugs can be improved if the practice of granting patents on newly developed life-sustaining drugs were to be abolished everywhere.
Which of the following, if true, most seriously weakens the argument?
(A) In countries in which life-sustaining drugs cannot be patented, their manufacture is nevertheless a profitable enterprise.
(B) Countries that do not currently grant patents on life-sustaining drugs are, for the most part, countries with large populations.
(C) In some countries specific processes for the manufacture of pharmaceutical drugs can be patented even in cases in which the drugs themselves cannot be patented.
(D) Pharmaceutical companies can afford the research that goes into the development of new drugs only if patents allow them to earn high profits.
(E) Countries that grant patents on life-sustaining drugs almost always ban their importation from countries that do not grant such patents.
答案是D，请指教一下其中的逻辑，我觉得D是无关的阿 | 
