Which of the following statements is TRUE?

a.The number of hospitals in the U.S. has grown almost as fast as the number of physicians since 1974.

b.Doctors in the U.S. are typically direct employees of hospitals.

c.The fact that doctors are not employees of hospitals in the U.S. tends to undermine their incentive to help control hospital costs.

d.Nonprofit hospitals in the U.S. can raise funds by issuing stock.