Which of the Following Is a True Statement

Which of the following is a true statement?

A) While researchers found it difficult to reject the random walk hypothesis for exchange rates on empirical grounds, there is no theoretical reason why exchange rates should follow a pure random walk.
B) While researchers found it easy to reject the random walk hypothesis for exchange rates on empirical grounds, there are strong theoretical reasons why exchange rates should follow a pure random walk.
C) While researchers found it difficult to reject the random walk hypothesis for exchange rates on empirical grounds, there are compelling theoretical reasons why exchange rates should follow a pure random walk.
D) None of the above