Answer:
B) sale; decrease
Explanation:
The federal funds rate is the rate at which banks make overnight loans to other banks or financial institutions. If the supply of money is too high, then the interest rates will start to decrease.
Money is like any other good, and its price is determined by the supply and demand. The higher the supply, the lower the equilibrium price. The equilibrium price of money is the interest rate.
If the Fed wants to avoid the decrease in the interest rate, it must absorb excess supply of money, and the only way it can do it is by selling bonds.