In nuclear fission, which of the following quantity is conserved?

In a nuclear reaction, mass is not conserved. The difference in masses of reactants and product nuclei, known as the mass defect, is converted to an equivalent amount of energy according to Einstein's equation E=mc². However, total mass-energy is conserved, that is, the equivalent energy of the entire masses of reactants is the same as that of the products plus the energy of the radiations produced.