For Which of the Following Equilibria Does K_c Correspond to the Acid-Ionization

Multiple Choice

For which of the following equilibria does K_c correspond to the acid-ionization constant,K_a,of HC₂O₄^-?

A) HC₂O₄^-(aq) + H₂O(l) H₂C₂O₄(aq) + OH^-(aq)
B) H₂C₂O₄(aq) + H₂O(l) H₃O⁺(aq) + HC₂O₄^-(aq)
C) HC₂O₄^-(aq) + H₂O(l) H₃O⁺(aq) + C₂O₄^2-(aq)
D) HC₂O₄^-(aq) + OH^-(aq) C₂O₄^2-(aq) + H₂O(l)
E) HC₂O₄^-(aq) + H₃O⁺(aq) H₂C₂O₄(aq) + H₂O(l)