Respuesta :

Answer:

C.

Explanation:

"Cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and discarding, as waste products, carbon dioxide and water."

Answer:

its oxygen!

Explanation:

I just took this test on FLVS and this was a question, I answered with Oxygen and ended up with a 100% test score. Hope I could help!