[单项选择]

A
The cost of medical care in the United States is very high. The time and money that doctors spend on their medical education are probably one reason for this problem.
A visit to a doctor’s office costs from fifteen to fifty dollars. It is impossible to pay for the medical care they need. Many people in the United States think that doctors are overpaid. Most doctors, however, disagree. They say that they were required to study medicine for a long time. Tuition(学费)for many years of medical education costs a lot of money. Doctors say that it is necessary for most medical students to borrow money from a bank to pay their tuition. Because this money must be repaid to the bank, young doctors need a lot of money for their work. So, they charge people high prices for medical care. Therefore it is possible that the high cost of medical care in America is unnecessary. Because high tuition is one cause of high costs, one way to lower costs would be to have med
A. a visit to a doctor's office may cost as much as $ 15 to $ 50 in U. S.
B. the cost of medical care is the main reason for the high costs in the U. S.
C. medical care in the U. S. costs a lot of money because doctors want to be rich
D. the high cost of tuition in medical schools is one reason for the high cost of medical care in the U. S.