This is a simplified schematic of glycolysis. this is the first step in a) aerobic respiration. b) alcohol fermentation. c) aerobic respiration and fermentation. d) lactic acid and alcohol fermentation.

The correct answer is option C, that is, aerobic respiration and fermentation.  

Glycolysis refers to the procedure by which the glucose is dissociated with the help of various enzymatic catalyzed reactions yielding two molecules of pyruvate and a net energy of two molecules of ATP.  

It is the initial stage of both aerobic respiration and fermentation. Fermentation takes place during the devoid of oxygen and begins with glycolysis that leads to the formation of two pyruvate molecules that are then transformed into lactic acid.  

In aerobic respiration that takes place in the existence of oxygen, glycolysis is the initial phase, which is then succeeded by Kreb's cycle and the electron transport chain. All these stages elevate the production of energy in the form of ATP that is then used up by the cells or gets accumulated to drive the cellular procedures.

the scientific method.