Medical reporter: Studies have consistently found that taking an aspirin a day thins the blood slightly, thereby helping to prevent or reduce the severity of heart disease. Since heart disease is one of the most common types of ill health in industrialized nations, most people in such nations would ttherefore be in better health if they took an aspirin a day. The reasoning in the doctor's argument is most vulnerable to criticism on which one of the following grounds? ['It fails to address the possibility that the studies on the beneficial effects of aspirin were conducted only in industrialized nations.', 'It overlooks the possibility that preventing or reducing the severity of heart disease has little or no effect on any of the other most common diseases in industrialized nations.', 'It overlooks the possibility that even if a disease is one of the most common in a nation, most people in that nation are not in significant danger of developing that disease.', 'It takes for granted that if medication can reduce the severity of heart disease, it can also prevent some cases of heart disease.']