Answer:
D. all of these.
Step-by-step explanation:
Cellular respiration is a phenomenon that basically consists of the process of extracting chemical energy accumulated in molecules of various organic substances, such as carbohydrates and lipids.
The general equation for cellular respiration is: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + energy
From this equation we can see that during the breathing process glycogen and oxygen are used as reagents to form energy, water and carbon dioxide.