Does meditation cure insomnia? Researchers randomly divided 400 people into two equal-sized groups. One group meditated daily for 30 minutes, the other group attended a 2-hour information session on insomnia.

At the beginning of the study, the average difference between the number of minutes slept between the two groups was about 0. After the study, the average difference was about 32 minutes, and the meditation group had a higher average number of minutes slept.

To test whether an average difference of 32 minutes could be attributed to chance, a statistics student decided to conduct a randomization test. She wrote the number of minutes slept by each subject in the study on an index card. She shuffled the cards together very well, and then dealt them into two equal-sized groups, representing those who meditated and those who attended the information session.

Which of the following best describes the outcome of the randomization test.

A. The average difference between the two values on the two stacks of cards is expected to be about 0 minutes.

B. If meditation is effective, the average difference between the values on the two stacks of cards is expected to be more than 32 minutes.

C. The average difference between the two values on the two stacks of cards is expected to be about 32 minutes.