In the heath-care industry, the doctor-patient relationship is the mirror image of the original relationship between producer and consumer. Once an individual has chosen to see a physician--and even then there may be no real choice it is the physician who usually makes all significant purchasing decision: whether the patient should return "next Wednesday," whether X-rays are needed, whether drugs should be prescribed, etc. It is a rare and sophisticated patient who will challenge such professional decisions or raise in advance questions about price, especially when the ailment is regarded as serious.
This is particularly significant in relation to hospital care. The physician must certify the need for hospitalization, determine what procedures will be performed, and announce when the patient may be discharged. The patient may be consulted about some of these decisions, but in the main 'ii' is the doctor's judgments that are final. Little wonder then that in the eyes of the hospital it is the physician who is the real" consumer".
As a consequence, the medical staff represents the" power center" in hospital policy and decision making, not the administration.
Although usually there are in this situation four identifiable participants, the physician, the hospital, the patient, and the payer (generally an insurance carrier or government) the physician makes the essential decisions for all of them. The hospital becomes an extension of the physician; the payer generally meets most of the bona fide bills generated by the physician/hospital; and for the most part the patient plays a passive role. In routine or minor illness, or just plain worries, the patient's options are, of course, much greater with respect to use and price.
In illness that is of some significance, however, such choices tend to evaporate, and it is for ill ness that the bulk of the health-care dollar is spent. We estimate that about 75-80 percent of health care expenditures are determined by physicians, not patients. For this reason, economy measures directed at patients or the general public is relatively ineffective.
In what aspect is the health-care economy different from other sectors of economy？

A. The relationship between sellers and buyers.
B. The price of the products.
C. The quality of the products.
D. The regulations of health-care industry.