I'd personally say B because a warmup will reduce injury, soreness, and get you ready. Then you have your exercise. Then the cooldown helps <span>bring the heartrate down to near-normal and to get the blood circulating freely back to the heart. Stopping abruptly could result in fainting or place undue stress on the heart.</span>
-emia is referring to blood.
I think it is C, since it sounds the most reasonable.
The effects of fatigue are not classified as learning because they are not permanent effects.