Which of the following is formed when $SO_3$ is absorbed by concentrated $H_2SO_4$?

$A$ sulphate of a metal $(A)$ on heating evolves two gases $(B)$ and $(C)$ and an oxide $(D).$ Gas $(B)$ turns $K_2Cr_2O_7$ paper green while gas $(C)$ forms a trimer in which there is no $S-S$ bond. Compound $(D)$ with $HCl$ reacts to form a compound $(E)$ which exists as a dimer. Compounds $(A)$,$(B)$,$(C)$,$(D)$ and $(E)$ are respectively:

Write a short note on the anomalous behavior of oxygen.

The thermal stability of the hydrides of group-$16$ elements follows the order:

Explain variations in atomic radii and ionisation enthalpies in group-$16$.

Identify the incorrect statement regarding ozone $(O_3)$.