Which of the Following Problems Will Most Likely Occur with a System

Which of the following problems will most likely occur with a system of flexible exchange rates?

A) Macroeconomic instability as exports and imports fluctuate with the exchange rates.
B) Government favoritism toward selected importers of goods and services.
C) The emergence of black markets for foreign currency.
D) Distortions in trade patterns away from the pattern suggested by comparative advantage.