Answer:
option 3 lactic acid
Explanation:
In the muscle cell, during strenuous exercises, the oxygen cannot be taken to the respiratory system fast enough to allow for aerobic respiration to occur. thus, for continuous production of ATP, the muscle cell have to reduce pyruvate in the process of lactic acid fermentation to give rise to Lactic acid, ethanol and carbondioxide. this way, the cell can continue to produce ATP but in low amounts compared to aerobic respiration, although accumulation of lactic acid can lead to muscle fatigue and pain.
