The Fed Is Reluctant to Change the Required Reserve Rate

 The Fed is reluctant to change the required reserve rate because: ?

A)  changes in the rate have a small impact on the actual quantity of money.?
B)  the money multiplier is not impacted by the required reserve rate.?
C)  the time lag between changing the required reserve rate and changes in the money supply can be too long.?
D)  small changes in the required reserve rate can have too big of an impact on the money multiplier and the level of deposits.