Answer;
C. law of conservation of mass
Step-by-step explanation;
The law of conservation of mass, which is one of the basic laws of chemical combination. This law states that during a chemical reaction, the total mass of the products remains equal to the total mass of the reactants.
Balanced chemical equations must obey the Law of Conservation of Mass that states that matter cannot be created or destroyed, it is conserved. Atoms are never lost or gained in chemical reactions, they are rearranged. The mass of the reactants must equal the mass of the products.