Which of the following is not among the methods of cost control used by the government during recent decades?

A) Regulation of providers' prices cap on providers' revenues

B) Cap on providers' revenue

C) "Voluntary efforts" to have hosptials reduce their prices

D) Rationing of health care in general

E) Introducing, under the Patient Protection and Affordable Care Act, a 25% discount on prescription drugs to seniors whose spending on prescription drugs under Medicare has reached the "donut hole" (the spending range where Medicare does not pay for prescription drugs anymore and seniors are fully responsible for the cost of drugs out of pocket).