Which statement below best explains why fermentation occurs in mammals?
a. it enables mammals to generate additional ATP in an oxygen-rich environment.
b. it produces an acid that maintains blood pH within a narrow range.
c. it generates ethanol, which can be used as an alternative source of energy.
d. it allows glycolysis to continue under anaerobic conditions by replenishing NAD+
e. It breaks down lactic acid to generate a small amount of ATP under anaerobic conditions.