Which of the following formulas represents fuming sulfuric acid (oleum)?

Assertion : Dinegative anion of oxygen $(O^{2-})$ is quite common but dinegative anion of sulphur $(S^{2-})$ is less common.
Reason : Covalency of oxygen is two.

Which of the following compounds has the maximum number of oxo groups $(M=O)$?

When $PbO_2$ reacts with conc. $HNO_3$,the gas evolved is:

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$ : Both rhombic and monoclinic sulphur exist as $S_8$ while oxygen exists as $O_2$.
Reason $(R)$ : Oxygen forms $p \pi-p \pi$ multiple bonds with itself and other elements having small size and high electronegativity like $C, N$,which is not possible for sulphur.
In the light of the above statements,choose the most appropriate answer from the options given below:

In which of the following is the formation of polyanions maximum?