A result of the common-ion effect is __________. A) that some ions, such as Na+ (aq), do not participate in solubility equilibria B) that common ions, such as Na+ (aq), don't affect equilibrium constants C) that ions such as K+ and Na+ are common ions, so that their values in equilibrium constant expressions are always 1.00 D) that common ions precipitate all counter-ions E) that the selective precipitation of a metal ion, such as Ag+, is promoted by the addition of an appropriate counterion (X-) that produces a compound (AgX) with a very low solubility