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