For the Reaction, D₂(s)+ 2 AX(g) $\rarr$ A₂(g)+ 2 DX(g)taking Place in an Insulated System, the Enthalpy

For the reaction, D₂(s) + 2 AX(g) $\rarr$ A₂(g) + 2 DX(g) taking place in an insulated system, the enthalpy of the reactants is lower than that of the products. Which one of the following is true for the system?

A) The energy of the system decreases as the reactants are converted to products.
B) The energy of the system increases as the reactants are converted to products.
C) The total energy of the system decreases as the reactants are converted to products.
D) The total mass of the system decreases as the reactants are converted to products.
E) The total mass of the system increases as the reactants are converted to products.