Which of the following is correct concerning hess's law?

a-the change of enthalpy of a reaction can be found be subtracting the enthalpy of the products from the enthalpy of the reactants.

b-the change in enthalpy can be found be subtracting the enthalpy of the reactants from the enthalpy of the products.

c-the change in enthalpy can be found by adding the enthalpies of the individual thermochemical reactions of a chemical reaction.

d-the change in enthalpy can be found by subtracting the enthalpies of the individual thermochemical reactions of a chemical reaction.