The United States a. was on a fixed exchange rate system prior to late 1971, but now is on a flexible exchange rate system. b. has been on a fixed exchange rate system since 1945. c. has been on a...

a. was on a fixed exchange rate system prior to late

1971, but now is on a flexible exchange rate

system.

b. has been on a fixed exchange rate system since

1945.

c. has been on a flexible exchange rate system since

1945.

d. was on a flexible exchange rate system prior to

late 1983, but now is on a fixed exchange rate

system.