Use the Following Information for Questions

Multiple Choice

Use the following information for questions:
43 sedentary adults between the ages of 50 and 76 were randomly assigned to either an exercise program four times a week for 16 weeks or they continued to be sedentary (King, et al, JAMA, January 1, 1997,pp 32-37) . The exercise group slept an average of 42 minutes a night longer than the control group.
-Can a conclusion that the exercise program caused more sleep?

A) A cause and effect relation might be concluded because the study had a control group.
B) A cause and effect relation might be concluded because the study was a randomized experiment.
C) A cause and effect relation cannot be concluded because the study was an observational study.
D) A cause and effect relation cannot be concluded because diet was not controlled.