Oxygen does not react directly with which of the following?

Which of the following statements is correct regarding the oxygen family (Group $16$)?
$(i)$ The stability of $+6$ oxidation state decreases down the group and the stability of $+4$ oxidation state increases down the group.
$(ii)$ The stability of $+6$ oxidation state increases down the group and the stability of $+4$ oxidation state decreases down the group.
$(iii)$ Bonding in $+4$ and $+6$ oxidation states is primarily covalent.

The photoconductor used in a xerox machine is ....

The correct sequence of decreasing number of $\pi$-bonds in the structures of $H_2SO_3$,$H_2SO_4$,and $H_2S_2O_7$ is:

The oxoacid of sulphur that does not contain a bond between sulphur atoms is

The acid having $O - O$ bond is