Respuesta :
The study of human behavior is called psychology.
The correct answer is A.
In an experiment, scientist follows up two groups of species in which one group is the main species in which the drugs are experimenting while the other group is nonexperimenting group to find out the difference between the symptoms.
According to the question, Michael's grandmother is in another group and that group is known as a controlling group.
Hence, the correct answer is A that is a control group.
For more information, refer to the link:-
https://brainly.com/question/12985618