In the Reaction HSO₄^-(aq) + OH^-(aq) $\leftrightharpoons$ SO₄^2-(aq) + H₂O(l), the Conjugate Acid-Base Pairs Are

In the reaction HSO₄^-(aq) + OH^-(aq) $\leftrightharpoons$ SO₄^2-(aq) + H₂O(l) , the conjugate acid-base pairs are
$~~~~~~~~~\text { pair } 1 \quad~~~~~~~~~~~~~~~~~ \text { pair } 2$
A. $\mathrm{HSO}_{4}^{-}$ and $\mathrm{SO}_{4}{ }^{2-} ; \quad\mathrm{H}_{2} \mathrm{O}$ and $\mathrm{OH}^{-}$
B. $\mathrm{HSO}_{4}^{-}$ and $\mathrm{H}_{3} \mathrm{O}^{-} ; \quad\mathrm{SO}_{4}{ }^{2-}$ and $\mathrm{OH}^{-}$ .
C. $\mathrm{HSO}_{4}^{-}$ and $\mathrm{OH}^{-} ; \quad \mathrm{SO}_{4}^{2-}$ and $\mathrm{H}_{2} \mathrm{O}$ .
D. $\mathrm{HSO}_{4}{ }^{-}$ and $\mathrm{H}_{2} \mathrm{O}; \quad\mathrm{OH}^{-}$ and $\mathrm{SO}_{4}{ }^{2-}$
E. $\mathrm{HSO}_{4}^{-}$ and $\mathrm{OH}^{-} ; \quad \mathrm{SO}_{4}{ }^{2-}$ and $\mathrm{H}_{3} \mathrm{O}^{+}$

A) A
B) B
C) C
D) D
E) E