What is one cited reason why healthcare expenditures are so high in the United States?

a.   Medicare and Medicaid reduce the supply of medical care.

b.   Doctors know patients are likely covered by insurance, which reduces the demand for medical care.

c.   Insurance companies attempt to control medical care costs by capping expenditures.

d.   The uninsured often seek care from emergency rooms, where medical care is more expensive.

 e.   Patients covered by insurance consume too little health care.