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.
-What is the explanatory variable in the study?

A) Amount of food eaten (calories) per day
B) Following an exercise program four times a week for 16 weeks (or not)
C) Amount of sleep per night
D) Age