Answer:
D) would reduce the multiplier. If the Fed wanted to offset the effect of this on the size of the money supply, it could have bought bonds
Step-by-step explanation:
Banks "create" money when they use their clients' money to make loans to other clients. If the banks' clients started to withdraw significant amounts of money, that would reduce the banks' capability of creating money which in turn would reduce the money multiplier. If the FED had bought bonds from private investors then they would have increased the money supply and probably also increased the money multiplier.