Which Statement About a Balanced Chemical Reaction Equation Is Always

Which statement about a balanced chemical reaction equation is always correct?

A) The total number of moles of the products equals the total number of moles of the reactants.
B) The number of atoms of each kind is the same for the products as for the reactants.
C) The sum of the stoichiometric coefficients for the products equals the sum of the stoichiometric coefficients for the reactants.
D) The sum of the masses of all gaseous products equals the sum of the masses of the gaseous products.
E) The sum of the masses of solid products equals the sum of the masses of solid reactants.