Which of the following is a correct explanation for why the aggregate demand curve slopes downward?
a. As the price level decreases exports become more expensive overseas and imports become relatively less expensive domestically, and thus net exports rise.
b. As the price level decreases, the real value of cash balances increases total expenditures rise.
c. As the price level decreases consumers substitute more expensive goods for less expensive choices.
d. As the price level decreases the labor force increases