The function of theis to allow an exchange between nutrients and waste material between blood and tissue.

Capillaries.

Explanation:

Capillaries are tiny vessels that branch out from arterioles to form networks around body cells. there are also capillaries located in the lungs, these absorb oxygen from air we inhale into the bloodstream and release carbon dioxide from our bloodstream for exhalation.

between the two muscle layers is the myenteric or auerbach's plexus, which controls peristalsis. in the colon, the muscularis externa is much thicker because the feces are large and heavy, requiring more force to push along. the stomach has a third layer of muscularis externa: the inner oblique layer.

answer: the answer is d.

explanation: this is because when you exercise you make your muscle produce a certain liquid, that does not evaporate it.   also when you exercise you do not reduce muscle fiber.   and it does not really control your twitch that much.