Answer:
The correct answer will be- Oxygen
Step-by-step explanation:
Cellular respiration is a complex process which breakdown the sugar molecule to produce the energy required by the cell to perform cellular functions.
The molecule prefered by the cell used as energy molecule is ATP which is released by the respiration.
The respiration can take place in both the presence and absence of oxygen but the amount of ATP varies in both.
The ATP production is higher in the respiration taking place in the presence of oxygen compared to the absence of oxygen.
Thus, oxygen is the correct answer.