Which Statement Is Accurate Regarding Social Security and Medicare

Which statement is accurate regarding Social Security and Medicare?

A) The Social Security deficit can be corrected with some reasonable adjustment, but the future Medicare cost problem appears intractable.
B) Because Social Security promises a service benefit, its costs are held hostage to rising health care costs.
C) Because Medicare provides a cash benefit, the future costs are quite predictable.
D) Medicare provides a benefit that is clearly defined by regulations for everyone who is covered while Social Security benefits depend on market forces.