State whether each of the following statements is true or false. Explain your answers in one or two sentences.

a. When commodity money is the only type of money, a decrease in the price of the commodity serving as money is inflation.

b. The same money is always used as both a unit of account and a medium of exchange at any one time in any one country.

c. The smaller the reserve ratio at banks, the larger the money multiplier.

d. The Federal Reserve reduces reserves by buying government bonds.