In the Following Reaction,which Reactant Is a Brønsted-Lowry Acid? Na₂HPO₄(aq)

In the following reaction,which reactant is a Brønsted-Lowry acid? Na₂HPO₄(aq) + H₂CO₃(aq) → NaH₂PO₄(aq) + NaHCO₃(aq)

A) Na₂HPO₄
B) H₂CO₃
C) NaH₂PO₄
D) NaHCO₃
E) none of the above