Answer
(d) $S{O_3}^{2-}$
Work Step by Step
(a) and (b): $Br^-$ and $N{O_3}^-$ are both anions of strong acids; therefore, they are pH-neutral.
(c) $HS{O_4}^-$ acts as an acid when dissolved in water.
(d) $S{O_3}^{2-}$ reacts with water to produce $HS{O_3}^-$ and $OH^-$, forming a basic solution.
