Which of the following accurately describes fermentation?
a. fermentation generates more atp than cellular respiration.
b. fermentation always produces carbon dioxide.
c. fermentation makes nad+ needed to keep glycolysis going.
d. fermentation can only occur in the presence of oxygen.

The right answer is C

In the anaerobic mode, the reduction of pyruvate to lactate or ethanol (fermentations) ensures the reoxidation of NADH to NAD + consumed during the oxidation of glyceraldehyde 3-phosphate to 1,3-bisphosphoglycerate (reaction 6 of glycolysis). This regeneration of NAD + allows glycolysis to be maintained in the absence of oxygen.

In the aerobic mode, NAD + is regenerated by the respiratory chain.