If the Fed wanted to increase the money supply it will use each
tool in the following way:
Open market operation: the Fed will buy more and more bonds
from the market and general public. It will release more money in
the market and increase the money supply in the market.
Reserve rate: reserve rate the amount of funds the banks always
have to keep with them. IF the reserve rates are low that means the
funds with the banks are less and they can lend more increasing the
money supply.
Discount rate: They are the rates at which the Federal bank
lend the money to the banks. to increase the money supply they will
reduce the rates and this will allow the banks to get more funds at
a cheaper rate.