Help .-.
Why is it best to include both exercise and calorie-reduction in a weight-loss plan?

A. Dieting without exercising places an overwhelming amount of stress on the heart.

B. You won't be able to lower your weight without both exercise and calorie-reduction.

C. You'll be unable to fight off viral illnesses if you reduce calories but don't exercise.

D. If you only cut back on calories, you're more likely to regain the weight.