Answer:
Lactic acid
Step-by-step explanation:
Carbon dioxide and water are both released as a result of aerobic respiration. Carbon dioxide is also released during anaerobic respiration in plants.
Ethanol is released during anaerobic respiration in yeast and plants.
Lactic acid is unique to anaerobic respiration in animals. After glycolysis, in the absence of oxygen, pyruvate is converted to lactic acid. This is why your muscles get sore and cramp up when you exercise vigorously!
A picture comparing these processes is attached