Answer:
The correct answer is option 3. removal of hydrogen atoms from lactic acid.
Explanation:
In anaerobic conditions, it ferments to generate lactic acid. It is two way or reversible process in which oxidation of lactic acid produces pyruvic acid and NADH.
This process involves the removal of hydrogen atoms from the lactic acid and produces NADH and H⁺ in the presence of lactate dehydrogenase enzyme and convert into pyruvic acid.
Thus, the correct answer is option 3. removal of the hydrogen atoms from lactic acid.