The gland that controls formation would be testes.
I believe the correct answer from the choices listed above is the third option. It is oxygen that is a necessary reactant for cellular respiration to occur. Cellular respiration, in a sense, is breaking down sugar in the presence of oxygen. Hope this answers the question.
Without sunlight plants can undergo photsynthesis and cannot produce oxygen for humans to breathe and would cause the humankind to go extinct.
Thermodynamics is the correct answer.
