Select the answer that correctly describes the effect on the money supply of the following monetary policy:

The Fed announces that they will change the discount rate from $4\mathrm{.}25\%$ to $4\mathrm{.}5\%$

Question $12$ options:

a$)$

Increases excess reserves and the money supply.

b$)$

Decreases excess reserves and the money supply.

c$)$

Does not change the reserves or the money supply.