Two alternative drugs are available to prevent blood clots from developing after a heart attack. According to two major studies, drug Y does this no more effectively than the more expensive drug Z, but drug Z is either no more or only slightly more effective than drug Y. Drug Z' s manufacturer, which has engaged in questionable marketing practices such as offering stock options to doctors who participate in clinical trials of drug Z, does not contest the results of the studies but claims that they do not reveal drug Z' s advantages. However, since drug Z does not clearly treat the problem more effectively than drug Y, there is no established medical reason for doctors to use drug Z rather than drug Y on their heart-attack victims. A major flaw in the argument is that the argument ['fails to recognize that there may be medical criteria relevant to the choice between the two drugs other than their effectiveness as a treatment', "neglects to compare the marketing practices of drug Y's manufacturer with those of drug Z's manufacturer", 'confuses economic reasons for selecting a treatment with medical reasons', 'does not consider drugs or treatments other than drug Y and drug Z that may be used to prevent blood clotting in heart-attack patients']