Final answer:
The answer is B. Pyruvate
Step-by-step explanation:
The correct answer is B. pyruvate.
Fermentation is a metabolic process that occurs in the absence of oxygen and uses organic molecules as a final electron acceptor to regenerate NAD+ from NADH, allowing glycolysis to continue. It does not involve an electron transport system and does not produce ATP directly.
During fermentation, pyruvate can be converted into different end products depending on the organism. For example, in lactic acid fermentation, pyruvate is converted into lactic acid. In alcohol fermentation, pyruvate is converted into ethanol. However, pyruvate itself is not an end product of fermentation.