Answer:
control group
Step-by-step explanation:
In this scenario, it can be said that Bob is in the control group of the experiment. In an experiment, the control group is the group that does not receive the variable that is being tested and instead receives a placebo that does not have any effect on the test subject, thus allowing the researchers to control the outcome of that group and compare it with the other groups. Which in this case the variable being tested is Ritalin.