Hello! I'm going to assume you meant carbon dioxide. If so, your answer would be C, a carbohydrate.
Photosynthesis takes three reactants to make two products. It uses CO2, water, and light to make glucose and oxygen.
More specifically, where carbon dioxide is converted is called the Calvin Cycle. This reaction takes place in the stroma, and it converts 6 molecules of CO2 into 1 molecule of glucose. (This is a very brief description, there are more products and reactants and it's a complex reaction)
Glucose is a carbohydrate. Carbohydrates are also called sugars, and glucose is a form of a sugar. Most sugars have a formula that is a multiple of CH20, and if you look at glucose's formula, C6H12O6, you see that it is a multiple. Therefore, carbon dioxide is converted to glucose, or a carbohydrate.
Hope this helps!
