Respuesta :
The answer to the question is D as the purpose for a control group is to be a comparison to the experimental group (the group that is a part of the experiment)
Answer:
D
Explanation:
an example is a person who wants to test if a particular pill makes people run faster. He gets a control group and a test group. After observing the 2 groups he compares the control group to the test group. So control groups are used for comparison to see if the hypothesis is correct or it is just a mare assumption or coincidence