Which aerobic exercise plan is the most well-balanced?
A. 15 minutes to warm up, 15 minutes of aerobic activity, 15 minutes to cool down B. 5 minutes to warm up, 25 minutes of aerobic activity, 0 minutes to cool down
C. 0 minutes to warm up, 15 minutes of aerobic activity, and 15 minutes to cool down
D. 5 minutes to warm up, 20 minutes of aerobic activity, 5 minutes to cool down