Gabriel is 22 years old and fairly sedentary, but he wants to be more physically active in order to get in shape and lose some weight. He does not enjoy vigorous exercise at all; the last time he started an exercise program, he tried running and quit after a week. What kind of exercise program would you recommend for Gabriel? a. 5 or more days per week of vigorous-intensity exercise for 20 minutes b. 5 or more days per week of moderate-intensity exercise for 60 minutes c. 2-3 days per week of moderate-intensity exercise for 30 minutes d. 2-3 days per week of vigorous-intensity exercise for 20 minutes