It is proposed to allow the sale, without prescription, of a medication that physicians currently prescribe to treat the common ear inflammation called "swimmer' s ear. " The principal objection is that most people lack the expertise for proper self-diagnosis and might not seek medical help for more serious conditions in the mistaken belief that they have swimmer' s ear. Yet in a recent study, of 1, 000 people who suspected that they had swimmer' s ear, 84 percent had made a correct diagnosis -- a slightly better accuracy rate than physicians have in diagnosing swimmer' s ear. Thus, clearly, most people can diagnose swimmer' s ear in themselves without ever having to consult a physician. Which one of the following, if true, most undermines the conclusion? ["Cases in which swimmer's ear progresses to more serious infections are very rare.", "For many people who develop swimmer's ear, the condition disappears without medical or pharmaceutical intervention.", 'Physicians who specialize in ear diseases are generally able to provide more accurate diagnoses than those provided by general practitioners.', "Most of the people who diagnosed themselves correctly had been treated by a physician for prior occurrence of swimmer's ear."]