Answer: C. H2O
Explanation: Living things composed of many molecules. Which are water , fats , carbohydrates , proteins. Gases include oxygen , carbon dioxide , carbon monoxide , hydrogen etc. Body also contains ions such as sodium , phosphate , potassium etc.
Water is body's main component. The amount of Water in human body is around 55- 60 percent. The percent of water in infants is high around 75-85 percent.
