Suppose the Fed wishes to use monetary policy to close an expansionary gap.a. Should the Fed increase or decrease the money supply?b. If the Fed uses open-market operations, should it buy or sell government securities?c. Determine whether each of the following increases, decreases, or remains unchanged in the sort run: the market interest rate, the quantity of money demanded, investment spending, aggregate demand, potential output, the price level, and equilibrium real GDP.