^&* 3. Efficient Markets Hypothesis (LO2, CFA1) After lengthy trial and error, you discover a trading system that would have doubled the value of your investment every six months if applied over the last three years. Which of the following problems makes it difficult to conclude that this is an example of market inefficiency?

a. Risk adjustment problem

b. Relevant information problem

c. Dumb luck problem

d. Data snooping problem