When a Small Amount of Hydrochloric Acid (HCl) Is Added

When a small amount of hydrochloric acid (HCl) is added to a solution of Na₂HPO₄, the pH of the solution does not change markedly.The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution.Based on these observations, the compound Na₂HPO₄ is:

A) able to donate hydrogen atoms to HCl.
B) able to remove hydrogen ions from the OH ^- of NaOH.
C) acting as a buffer.
D) an enzyme facilitating the reaction between HCl and NaOH.
E) acting as a solvent.