When a Small Amount of HCl or NaOH Is Added

When a small amount of HCl or NaOH is added to a solution of Na₂HPO₄, the pH of the solution barely changes. Based on these observations, all of the following are true concerning the compound Na₂HPO₄, except

A) Na₂HPO₄ is able to accept extra hydrogen ions from the HCl.
B) Na₂HPO₄ adsorbs excess H⁺ and OH^- directly onto the surface of its crystalline structure.
C) Na₂HPO₄ is able to donate hydrogen ions to the OH^- from NaOH.
D) Na₂HPO₄ acts as a buffer.
E) Na₂HPO₄ is a salt formed from reacting a strong base with a weak acid.