The correct choice is:
b. The Board of Governors direct monetary policy and set the discount rate while the Federal Open Market Committee oversees open market operations and sets the target federal funds rate.
The Board of Governors is responsible for the overall direction of monetary policy and has the authority to set the discount rate. The Federal Open Market Committee (FOMC), which includes members of the Board of Governors and other Federal Reserve Bank presidents, is primarily responsible for conducting open market operations and setting the target federal funds rate.