Ermentation reactions A. completely oxidize glucose to carbon dioxide and water B. often require the reactions of glycolysis to provide energy as ATP C. supply NAD for the oxidation of glucose D. operate in the presence of oxygen E. two of the above are correct

E. two of the above are correct

Explanation:

Fermentation reactions are processes that occur without the presence of oxygen and promote the release of energy (ATP) anaerobically. For these reactions to occur, glycolysis and reduction of pyruvate must occur.

These reactions allow the regeneration of NAD + that is necessary for the breakdown of glucose during the process called glycolysis, which is primarily responsible for the production of ATP. NAD + is regenerated from NADH.

With that, we can conclude that the correct options are:

B. often require the reactions of glycolysis to provide energy as ATP

C. supply NAD for the oxidation of glucose