Answer:
Aerobic metabolism is the most efficient way of producing ATP; it produces significantly more ATP for each molecule of glucose than anaerobic metabolism. Although the primary source of ATP in aerobic metabolism is carbohydrates, fatty acids and protein can also be used as fuel to generate ATP.
I believe it’s A. Not sure though
Oxygen-poor blood goes into the lungs and through the lung capillaries after leaving the heart. It does so to be oxygenated by the lungs. The oxygen in the lungs comes from the air we breath. Once the blood is oxygenated, it goes back into the heart, to be pumped back into our bodies for distribution.