If `Delta H` is the change in enthalpy and `Delta U` the change in internal energy accompanying a gaseous reaction (A) `Delta H` is always greater than `Delta U` (B) `Delta H`<`Delta U` only if the number of moles of the products is greater than the number of the reactants (C) `Delta H` is always less than `Delta U` (D) `Delta H`<`Delta U` only if the number of moles of the products is less than the number of the reactants