Which of the following is not a way in which an enzyme can speed up the reaction that it catalyzes?

a. the active site of the enzyme can provide a microenvironment with a different ph that facilitates the reaction.
b. the active site can provide heat from the environment that raises the energy content of the substrate.
c. binding of the substrate to the active site can stretch bonds in the substrate that need to be broken.
d. the enzyme binds a cofactor that interacts with the substrate to facilitate the reaction.
e. the binding of two substrates in the active site provides the correct orientation for them to react to form a product.