Each of the Following Is a Principle That Guided the Post-World

Each of the following is a principle that guided the post-World War II international monetary system except

A) a world currency should be created along with a world central bank and a world government.
B) in ordinary times, exchange rates should be fixed: fixed exchange rates encouraged international trade by making the prices of goods made in a foreign country predictable.
C) in extraordinary times, exchange rates should be changed.
D) an institution was needed to watch over the international financial system.