Answer: Glycolysis
Explanation: In cellular respiration, glucose and oxygen reacts to form adenosine tri phosphate which is the basis for all the metabolic reactions taking place in our body.
The aerobic respiration has three stages in which the glycolysis part can be aerobic or anaerobic depending on the situation.
Rest of the steps like Kreb's cycle and Oxidative phosphorylation are aerobic processes.
So, the correct answer is glycolysis.
