Answer:
The participants who were given the coffee
Step-by-step explanation:
This is the group which the experiment is centered or focused around in order to achieve a result of derive informations regarding their exposure to some things.
Dr. Sampson is studying the effects of caffeine on hunger which means 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. All this talks about The participants who were given the coffee being the experimental group