Option (C) is correct because during photosynthesis, carbon dioxide combines with water in the presence of sunlight to form carbohydrates. Photosynthesis is a process in which light energy is converted into chemical energy. This chemical energy is stored in carbohydrate molecules such as sugars.

Option (A) is not correct because protein is formed by protein synthesis. Protein synthesis is the process in which biological cells generate new proteins.

Option (B) is not correct because amino acids are formed by the Transamination reaction.

Option (D) is not correct because vitamins are made by living things. Vitamins are molecules made from the elements.