Suppose that currently we are in the era of ample reserves. The total amount of reserves in the banking system is $4 trillion. Which of the following monetary policy actions by the Fed will most likely cause the equilibrium federal funds rate to decrease? a. An open market purchase of $20 billion. b. Areduction in the discount rate. c. A reduction in the required reserve ratio. d. A reduction in the interest rate on reserves. e. None of the above.