Answer:
Control group
Explanation:
In a study to prove the effect of a substance on a person one group of people is adminitered the substance while another group is administered a different substance.
The members of the group do not know whether they have been administered the actual substance or not. If the substance is truly effective then the group which was administered the substance should show the effects of the substance while the other group should not show the effects.
The group to which the substance is not delivered is called the control group.
