The correct option is D.
Cellular respiration is the process by which the body breaks down the sugar molecules that are eaten in food with the aid of oxygen and covert them into energy, carbon dioxide and water are also produced as by products. Cellular respiration and fermentation are both involved in the breaking down of sugars but cellular respiration occurs in the presence of oxygen while fermentation occurs in the absence of oxygen. Carbon dioxide is breath out by the lungs during cellular respiration.
