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 HCO₃^-?

A) HCO₃^-(aq) + OH^-(aq) CO₃^2-(aq) + H₂O(l)
B) H₂CO₃(aq) + H₂O(l) HCO₃^-(aq) + H₃O⁺(aq)
C) HCO₃^-(aq) + H₂O(l) H₂CO₃(aq) + OH^-(aq)
D) HCO₃^-(aq) + H₃O⁺(aq) H₂CO₃(aq) + H₂O(l)
E) HCO₃^-(aq) + H₂O(l) CO₃^2-(aq) + H₃O⁺(aq)