If the United States fixes the exchange rate of Indian rupees per dollar at 45 rupees per dollar, then to maintain it at that rate

a. Indian and American exporters and importers must agree to keep their mutual trade in balance.

b. Indian and American exporters and importers must agree not to trade at any other exchange rate.

c. The U.S. government must do the exporting and importing for the United States.

d. both the U.S. and Indian governments must do the exporting and importing for their respective countries.

e. the U.S. government must buy and sell U.S. dollars on the foreign exchange market.