Which tool of monetary policy is most likely being described by each of the following statements?

a. It's the major way the Federal Reserve System enacts monetary policy.

b. This tool is good for emergency situations that require major, large-scale action.

c. This tool goes through the Federal Reserve's role as lender of last resort.

d. This tool is best for everyday monetary policy.

e. A major disadvantage of this tool is that it requires that banks want to borrow from the Fed.

f. Even if they aren't interested in buying, selling, or borrowing from the Fed. changes in this tool may inconvenience bank managers.