Which of the following explains conservation of mass during during cellular respiration

The law of conservation of mass states that in a chemical reaction, mass is neither created nor destroyed. That means, the total mass for the reactants needs to equal the total mass of the products. The reactants for photosynthesis are 6 carbon dioxide, 6 water and sunlight. The mass of these reactants adds to equal the mass of the products, which are 1 glucose and 6 oxygen.

C- a hypothesis or d- an observation