The correct option is C Glycolysis, Krebs cycle and Electron Transport Chain only
Cellular respiration involves following three processes:
1. Glycolysis - It is the process in which Glucose (a 6-carbon compound) is converted into Pyruvic acid (3-carbon compound).
2. Krebs cycle - It is the process in which Pyruvic acid undergoes a series of reaction by which most living cells produce energy molecules. It is an aerobic process.
3. Electron Transport Chain - It is a process in which ATP is produced using the proton gradient created across a membrane.