Final answer:
The experimental group is the group that received the drug, while the control group is the group that received the placebo.
Step-by-step explanation:
The experimental group is the group that received the drug. In this case, James administered the drug to one of his classes, so that class is the experimental group. The control group is the group that received the placebo. James gave the other class a placebo, so that class is the control group.