Biology

Muscle cells undergo lactic acid fermentation during intense exercise.

When muscles are working intensely and oxygen supply is limited, muscle cells switch to lactic acid fermentation to produce ATP quickly. This process allows glycolysis to continue by converting pyruvate into lactic acid, but it can lead to muscle fatigue and soreness.

The other options are incorrect:

Human muscle cells do not produce oxygen. Oxygen is taken in from the environment through the respiratory system and used in aerobic respiration.