When the nominal rate of interest and the rate of inflation are the same, the real interest rate is zero

What are the marginal propensity to consume (MPC) and the marginal propensity to save (MPS)? How is the MPC related to the consumption function?

Spending by consumers on consumption goods, spending by businesses on investment goods, spending by government, and spending by foreigners on net exports make up

a. disposable national income b. the equilibrium economy c. aggregate supply d. aggregate expenditure e. discretionary spending