The process that requires molecular oxygen as a reactant is: the Electron Transport System.
The Electron Transport System consists of a number of electron transporters in the inner mitochondrial membrane that are charged with moving electrons from the NADH and FADH₂ to molecular oxygen.
The final result of the electron transport system is the reduction of oxygen to water.
So, of all of the options provided, that which requires molecular oxygen as a reactant is the electron transport system.
Learn more about the electron transport system here:
https://brainly.com/question/12838824
These are the options:
(a) Glycolysis
(b) Lactic acid production
(c) Electron transport system
(d) Fermentation
(e) None of the above.
