I think that the answer is d
Through cells on the surface of its body and also through the orifice at the top of its head
If oxygen is present, then glucose can be broken all the way down into carbon dioxide and water. This process is called aerobic respiration because it requires air (oxygen). In the absence of oxygen, the cell uses a process called anaerobic fermentation. or simply fermentation.
Mitochondrion is found outside of nucleus in animal cell .
So , i think the answer is B.
