Which Statement Concerning an Enzyme Is True

Which statement concerning an enzyme is true?

A) An enzyme increases the size of the equilibrium constant of the reaction it catalyzes.
B) An enzyme decreases the size of the equilibrium constant of the reaction it catalyzes.
C) An enzyme shifts the equilibrium so that more product is formed when equilibrium is reached.
D) An enzyme increases the rate of a chemical reaction by lowering the activation energy.
E) An enzyme slows down reactions that occur too rapidly to be effective in the body.