A Clinical Psychologist Has Developed a New Form of Psychotherapy

A clinical psychologist has developed a new form of psychotherapy to treat a particular personality disorder. In order to test its effectiveness, a group of people with the personality disorder is selected to receive the therapy for 8 weeks. A second group of people with the disorder is also created, but this group receives no therapy at all. At the
End of the 8 weeks, the mental health of people in both groups is assessed to evaluate the new psychotherapy. In this study, the people who did not receive any therapy would be in the:

A) control group.
B) experimental group.
C) sample group.
D) random group.