Oxoacids of Sulphur

There is no $\mathrm{S}-\mathrm{S}$ bond in

Which of the following are peroxoacids of sulphur?

Which of the following gases on dissolving in ${\mathrm{H}}_2{\mathrm{SO}}_4$ forms oleum?

How many peroxy linkages are present in ${\mathrm{H}}_2{\mathrm{S}}_2{\mathrm{O}}_8$?

The oxoacid of sulphur that does not contain bond between sulphur atom is:

Oxoacids are acids that contain oxygen. Sulphur is known to form many oxoacids such as ${\mathrm{H}}_2{\mathrm{SO}}_4, {\mathrm{H}}_2{\mathrm{SO}}_3$, etc. In oxoacids of sulphur, sulphur exhibits a tetrahedral structure when coordinated to oxygen. Generally, oxoacids of sulphur contain at least one $\mathrm{S}=\mathrm{O}$ bond and one $\mathrm{S}-\mathrm{OH}$ bond. Terminal peroxide groups, terminal $\mathrm{S}=\mathrm{S}$, terminal and bridging oxygen atoms and chains of ${(-\mathrm{S}-)}_{\mathrm{n}}$ are also observed in addition to $\mathrm{S}=\mathrm{S}$ and $\mathrm{S}-\mathrm{OH}$. 

Among the following, the correct formula of Marshall's acid is