How would the Fed's changing the discount rate affect the money supply?

What will be an ideal response?

When the Fed changes the discount rate, it changes the amount banks must pay to borrow money from the Fed. If the Fed raises the discount rate, it charges banks more to borrow money, making banks less likely to borrow and therefore, giving banks less money to loan out, which would reduce the money supply. Conversely, if the Fed lowers the discount rate, banks would borrow and loan out more money, which would increase the money supply.