The American Health Care System Invests Enormous Sums on Research,development,the

The American health care system invests enormous sums on research,development,the latest diagnostic equipment,and high salaries to attract many of the best medical researchers and practitioners in the world.This is possible because:

A) government regulations keep health care salaries high.
B) there are large profits to be made from health care in the United States
C) government regulations prevent health care salaries from becoming excessive
D) all of these choices
E) none of these choices