Which is the stable crystalline form of sulfur at room temperature?

Given below are two statements:
Statement $I$: The boiling point of hydrides of Group $16$ elements follows the order
$H_2O > H_2Te > H_2Se > H_2S$.
Statement $II$: On the basis of molecular mass,$H_2O$ is expected to have a lower boiling point than the other members of the group,but due to the presence of extensive $H$-bonding in $H_2O$,it has a higher boiling point.
In the light of the above statements,choose the correct answer from the options given below:

What are the products formed when ferrous sulphate $(FeSO_4 \cdot 7H_2O)$ is heated strongly?

There is no $S-S$ bond in

Identify the method used to obtain $SO_2$ gas in industry.

Which of the following compounds is most acidic in nature?