The correct response is:
It shows that no atoms have been gained or lost during the reaction.
This response demonstrates the Law of Conservation of Mass, which states that in a chemical reaction, the number of atoms of each element remains the same before and after the reaction. The balanced equation reflects that the total number of each type of atom on the reactants' side (2Fe^2O^3 and 3C) is equal to the total number of each type of atom on the products' side (4Fe and 3CO^2), indicating that mass is conserved.