How does the potential-energy diagram for a reaction indicate whether the reaction is endothermic or exothermic?
(A) An endothermic reaction has reactants that are lower in energy than products because energy is absorbed to form the products.
(B) An endothermic reaction has reactants that are higher in energy than products because energy is released to form the products.
(C) An exothermic reaction has reactants that are lower in energy than products because energy is released to form the products.
(D) An exothermic reaction has reactants that are higher in energy than products because energy is absorbed to form the products.