Modern physicians often employ laboratory tests, in addition to physical examinations, in order to diagnose diseases accurately. Insurance company regulations that deny coverage for certain laboratory tests ttherefore decrease the quality of medical care provided to patients. Which one of the following is an assumption that would serve to justify the conclusion above? ['Physical examinations and the uncovered laboratory tests together provide a more accurate diagnosis of many diseases than do physical examinations alone.', 'Many physicians generally oppose insurance company regulations that, in order to reduce costs, limit the use of laboratory tests.', 'There are some illnesses that experienced physicians can diagnose accurately from physical examination alone.', 'Many patients who might benefit from the uncovered laboratory tests do not have any form of health insurance.']