Sodium nitroprusside solution gives a purple colour in alkaline medium with the sulphide ion. Which anion gives this purple colour with this reagent without any further treatment of the solution?

1. A$\mathrm{S}{}_2\mathrm{O}{}_3{}^{2-}$
2. B$\mathrm{S}{}^{2-}$
3. C$\mathrm{SO}{}_3{}^{2-}$
4. D$\mathrm{SO}{}_4{}^{2-}$