Net exports might be a negative amount if Americans
a. decrease their holdings of foreign currencies, borrow from foreigners, or do a little of both.
b. increase their holdings of foreign currencies, borrow from foreigners, or do a little of both.
c. decrease their holdings of foreign currencies, lend to foreigners, or do a little of both.
d. increase their holdings of foreign currencies, lend to foreigners, or do a little of both.