Chemistry - GOC Question with Solution | TestHub

$\mathrm{C}$ is incorrect in a polar protic solvent. Sulfur is larger and more polarizable than oxygen and is less strongly solvated, so ${\mathrm{HS}}^{-}$ is more nucleophilic than ${\mathrm{OH}}^{-}$ even though it is less basic. $\mathrm{B}$ gives the correct polar-protic halide order ${\mathrm{I}}^{-}$ > ${\mathrm{Br}}^{-}$ > ${\mathrm{Cl}}^{-}$ > ${\mathrm{F}}^{-}$. The source explanation discussing $\mathrm{B}$ did not explain the incorrect option.