The Foreign Exchange Market Is NOT Efficient Because

The foreign exchange market is NOT efficient because

A) market participants do not compete with one another due to the fact that exchange takes place around the world and not in a single centralized location.
B) dealers have ask prices that are higher than bid prices.
C) central governments dominate the foreign exchange market and everybody knows that by definition, central governments are inefficient.
D) none of the reasons listed are accurate because the foreign exchange market is efficient.