Dr Hu Is Concerned About Cheating in His Abnormal Psychology

Dr. Hu is concerned about cheating in his abnormal psychology class. He decides to give two different versions of his final exam and finds that students performed better on one version than the other. He concludes that the students who did poorly must have cheated off students with the other form. This conclusion is:

A) Correct - good for him for catching the cheaters
B) Incorrect - there are too many other factors that could have influenced the difference
C) Incorrect - he may not have made sure each version of the test was equivalent
D) Inconclusive - based on this limited information, he could be right or wrong