Which of the following elements belongs to the halogen group?

Which of the following represents the correct order for oxidising power of the given species $ClO_4^{-}$,$BrO_4^{-}$,and $IO_4^{-}$?

The correct statement$(s)$ about the oxoacids,$HClO_4$ and $HClO$,is(are):
$[A]$ $HClO_4$ is more acidic than $HClO$ because of the resonance stabilization of its anion.
$[B]$ $HClO_4$ is formed in the reaction between $Cl_2$ and $H_2O$.
$[C]$ The central atom in both $HClO_4$ and $HClO$ is $sp^3$ hybridized.
$[D]$ The conjugate base of $HClO_4$ is a weaker base than $H_2O$.

The chief source of iodine in which it is present as sodium iodate is

All the compounds listed in Column $I$ react with water. Match the result of the respective reactions with the appropriate options listed in Column $II$.

Column $I$	Column $II$
$(A). (CH_3)_2 SiCl_2$	$(p).$ Hydrogen halide formation
$(B). XeF_4$	$(q).$ Redox reaction
$(C). Cl_2$	$(r).$ Reacts with glass
$(D). VCl_5$	$(s).$ Polymerization
	$(t). O_2$ formation

The anhydride of the oxoacid $HOCl$ is