Proponents of the Fixed Exchange Rate System Argue That

Proponents of the fixed exchange rate system argue that

A) flexible exchange rates may promote international trade,but under a fixed exchange rate system at least we know what the rates will be from day to day.
B) under a flexible exchange rate system,there is too great a chance that the exchange rate will diverge from the equilibrium exchange rate.
C) under a flexible exchange rate system,there is no way of knowing what the exchange rate is at any particular point in time.
D) under a fixed exchange rate system,there would be only one currency.
E) none of the above