Which of the Following Equilibria Represents the Second Ionization Step

Which of the following equilibria represents the second ionization step of H₃PO₄?

A) H₃PO₄(aq) + H₂O(l) ⇌ H₂PO₄^-(aq) + H₃O⁺(aq)
B) H₃PO₄(aq) + 2H₂O(l) ⇌ HPO₄^2-(aq) + 2H₃O⁺(aq)
C) H₂PO₄^-(aq) + H₂O(l) ⇌ HPO₄^2-(aq) + H₃O⁺(aq)
D) HPO₄^2-(aq) + H₂O(aq) ⇌ PO₄^3-(aq) + H₃O⁺(aq)
E) H₃PO₄(aq) + 3H₂O(l) ⇌ PO₄^3-(aq) + 3H₃O⁺(aq)