How Does the Ion-Product of Water, K_w, Relate to the Equilibrium

How does the ion-product of water, K_w, relate to the equilibrium constant, K_eq, for the dissociation reaction of water?

A) K_w is found by multiplying K_eq by the concentration of water.
B) K_w just another symbol for K_eq , so they are equal.
C) K_w is found by dividing K_eq by the ideal gas constant.
D) K_w is found by multiplying K_eq by the concentrations of hydronium ion and hydroxide ion.