20. If the central bank wants to implement contractionary monetary policy to decrease output, the Federal Reserve should (more than one answer is correct):

a. sell government bonds, which will decrease the money supply; this will cause interest rates to rise and aggregate demand to fall.

b. buy government bonds, which will increase the money supply; this will cause interest rates to fall and aggregate demand to fall.

c. decrease the discount rate, which will lower the market rate of interest; this will cause both costs and prices to rise.

d. increase taxes and decrease government spending.

e. increase the target federal funds rate, which will raise the market rate of interest and cause aggregate demand to fall.