Which one is known as oil of vitriol?

When an inorganic compound reacts with $SO_2$ in an aqueous medium,it produces $(A)$. $(A)$ on reaction with $Na_2CO_3$ gives compound $(B)$,which with sulphur,gives a substance $(C)$ used in photography. Compound $(C)$ is:

Which of the following statements is not correct?

Provide information about the allotropes of sulfur.

Which form of sulphur shows paramagnetic behaviour?

Which element from the following belongs to the oxygen family?