X and Y are sodium salts of Group 17 elements. If X is treated with concentrated sulfuric acid, hydrogen sulfide, $\mathrm{H_2S}$, is formed. If Y is treated with concentrated sulfuric acid, the oxidation number of sulfur does not alter. Which statement is correct?
- AAqueous X reduces aqueous bromine.
- BAqueous Y reacts with aqueous silver nitrate to give a precipitate which is insoluble in concentrated aqueous ammonia.
- CX and Y react separately with concentrated sulfuric acid to produce halogens.
- DWhen X reacts with concentrated sulfuric acid, six halide ions are needed to reduce one sulfur atom to $\mathrm{H_2S}$.