Question 21 (2.5 points) Of the following, which is not true? 1) the Fed can precisely control the Monetary Base 2) Keynesian economists believe the key financial variable for changing economic activity is the money supply 3) it is virtually impossible to sell CP with unless it has an A-1 or P-1 rating 4) when using the ordinary annuity formula, the present value computed is as of one period before the first payment