The Nurse Is Critiquing a Research Study That Involves Participants

The nurse is critiquing a research study that involves participants undergoing chemotherapy for breast cancer.Which finding would meet a criterion for inferring causality between performance of exercise and adaptive behaviour of the participants receiving chemotherapy?

A) Adaptation behaviour began before the exercise program was initiated.
B) Adaptive behaviour occurred in the control group over time.
C) The level of adaptation behaviours increased proportionately with increase in the intensity of the exercise.
D) No differences in adaptation behaviours were observed between participants in the experimental group and participants in the control group.