In the Section "Investigating Life: Sniffing Out the Origin of Feathers",why

In the section "Investigating Life: Sniffing Out the Origin of Feathers",why does an animal with a high metabolic rate have a huge demand for oxygen?

A) Oxygen is needed by mitochondria to provide energy for homeostasis with energy from food.
B) Oxygen is used in fermentation to obtain maximal energy from food.
C) Oxygen is needed for cells to move rapidly.
D) Oxygen is needed for protein synthesis.
E) Oxygen is used by the cell to be able to grow rapidly.