6. Advertisement: For sinus pain, three out of four hospitals give their patients Novex. So when you want the most effective painkiller for sinus pain, Novex is the one to choose. Which of the following, if true, most seriously undermines the advertisement’s argument? (A) Some competing brands of painkillers are intended to reduce other kinds of pain in addition to sinus pain. (B) Many hospitals that do not usually use Novex will do so for those patients who cannot tolerate the drug the hospitals usually use. (C) Many drug manufacturers increase sales of their products to hospitals by selling these products to the hospitals at the lowest price the manufacturers can afford. (D) Unlike some competing brands of painkillers, Novex is available from pharmacies without a doctor’s prescription.（D） (E) In clinical trials Novex has been found more effective than competing brands of painkillers that have been on the market longer than Novex. 不理解啊,题目的意思应该是:因为3/4的医院给病人服用novex->novex是最有效的药 d里面说novex是非处方药 那么医院在能够给病人服处方药的时候还给病人服用novex,怎么undermine这个argument啦? | 
