Question 1: The Federal Reserve this option is unlike the others and is not a goal. The Federal Reserve is the central bank of the United States
Question 2: Fiscal policy. There are two ways to control the economy and that is a monetary policy which the Fed controls and then fiscal policy which certain part of government is can control.
Question 3: A recurring cycle of booms, busts recoveries, and recession. That is the definition of a business cycle.
Question 4: It can be three of these options, but the Feds mostly use the buying and selling of bonds in open market operations the most.