Which of the following is the correct net ionic equation for the addition of small amount of HCl to a buffer solution made with Na2HPO4/Na3PO4? (Answer chosen is not correct!!)

Which of the following is the correct net ionic equation for the addition of small amount of HCl to a buffer solution made with Na2 HPO4 /Na3 P04 ? HCl(aq) + Na2HPO4 NaH2 PO 4 HPO42- (aq) HCl(aq) + PO43- (aq) + C1- (aq) HCl(aq) + Naz PO4 Na2 HPO 4 H+ (aq) + PO43- (aq) HPO42- (aq) OH+ (aq) + Na2 HPO4 NaH2 PO 4(aq) + Na+ (aq)