Answer : The correct option is, (C) photosynthesis
Explanation :
Photosynthesis : It is a chemical process that occurs in the green plants. During photosynthesis process, carbon dioxide reacts with water in the presence of sunlight to gives glucose as a product and oxygen as a byproduct. In the photosynthesis reaction, carbon dioxide and water molecule are the reactants.
The balanced chemical reaction will be,

Whereas the combustion , decomposition and respiration are the chemical reactions in which the carbon dioxide is produced as a product.
Hence, the correct option is, (C) photosynthesis