Because of the threat of medical malpractice suits, many physicians are subjecting their patients to unnecessary medical testing. Physicians want to be able to explain their actions if anything goes wrong, and they want to be able to show that they tried everything to properly diagnose and treat an ailment. It is difficult for physicians to judge exactly how thorough they need to be in order to avoid potential liability. It is generally wise, ttherefore, for patients to avoid going to a physician unless the patients are very sick. Which one of the following, if true, would most seriously weaken the argument in the passage? ['Many diseases, if they are not caught early, can cause death.', 'Under pressure from the medical malpractice insurers, many doctors have raised their fees.', 'Most insurance companies subsidize the additional expense associated with unnecessary medical tests.', 'Patients are unable to determine what is the appropriate level of testing.']