What happens in Finkelstein reactions?

The following reaction,

$\mathrm{R}-\mathrm{X}+\mathrm{NaI}\to \mathrm{R}-\mathrm{I}+\mathrm{NaX}$  where, $\mathrm{X}=\mathrm{Cl},\mathrm{Br}$ is known as

The major product of the following reaction is:

Identify the reagent(s) '$\mathrm{A}$' and condition(s) for the reaction :

Identify $\mathrm{X}$ in the reaction given below

Identify compound $\left(\mathrm{C}\right)$ in the following reaction

${\mathrm{C}}_7{\mathrm{H}}_8\stackrel{3{\mathrm{Cl}}_2/\mathrm{\Delta }}{\to }\left(\mathrm{A}\right)\stackrel{{\mathrm{Br}}_2/\mathrm{Fe}}{\to }\left(\mathrm{B}\right)\stackrel{\mathrm{Zn}/\mathrm{HCl}}{\to }\left(\mathrm{C}\right)$

Major product P of above reaction, is:

Consider the given reaction, the Product $\mathrm{A}$ is:

For the given reaction:

What is $\mathrm{A}$?

The major product (Q) of the below reactions is

The major products, $\mathrm{P}$ and $\mathrm{Q}$, formed in the reactions given below are: