When a country runs a balance of payments deficit under a system of fixed exchange rates, which of the following is NOT part of the automatic process?
a. a decrease in money supply will lead to a lower level of spending
b. an increase in unemployment will lead to lower wages
c. a decrease in aggregate demand will lower domestic prices
d. an increase in tariffs will reduce the level of imports
e. a decrease in domestic prices relative to foreign prices will reduce the level of imports

单选，请解释原因，谢谢～