Dr Sampson Is Studying the Effects of Caffeine on Hunger

Dr. Sampson is studying the effects of caffeine on hunger. He hypothesizes that people who ingest more caffeine experience less hunger pangs throughout the day. He designs a study where one group of participants is given caffeine throughout the day, and the other group is not allowed to have any caffeine. He then has the two groups journal their hunger pangs throughout the day and he compares the results. In this study, the experimental group consists of the participants who:

A) were not allowed caffeine.
B) had the most hunger pangs.
C) did not have any hunger pangs.
D) were given the caffeine.