If the Federal Reserve Wants to Help Boost a Sagging

If the Federal Reserve wants to help boost a sagging economy,which one of the following is the most direct way it can do this?

A) Raise interest rates so that banks can earn more money on the loans they provide to individuals and businesses.
B) Lower interest rates so that banks can provide more loans at cheaper rates to individuals and businesses.
C) Take money out of circulation so that the dollar becomes more valuable.
D) Raise the reserve requirement,restricting the amount of cash and negotiable securities banks must have on hand.
E) Lower tariffs so that corporations can trade more freely with foreign countries.