A solution containing hydrogen phosphate ions, HPO₄²⁻, is titrated with HCl(aq) until it has been converted completely to dihydrogen phosphate ions. Which net ionic equation best represents the overall reaction?
a) PO43−(aq)+H+(aq)→HPO42−(aq)
b) HPO42−(aq)+H+(aq)→H2PO4−(aq)
c) HPO42−(aq)+2H+(aq)→H3PO4(aq)
d) HPO42−(aq)→H+(aq)+PO43−(aq)