HA Is a Weak Acid

Multiple Choice

HA is a weak acid.Which equilibrium corresponds to the equilibrium constant K_b for A^-?

A) HA (aq) + H₂O (l) H₂A⁺ (aq) + OH^-(aq)
B) A^- (aq) + H₃O⁺ (aq) HA (aq) + H₂O (l)
C) HA (aq) + OH^- (aq) H₂O (l) + H⁺ (aq)
D) A^- (aq) + H₂O (l) HA (aq) + OH^- (aq)
E) A^- (aq) + OH^- (aq) HOA^2- (aq)