Identify the major products $(P)$ and $(Q)$ respectively for the given reaction.

Given below are two statements:
Statement $I$: Due to increase in van der Waals forces, the order of boiling points is $CH_3CH_2CH_2I > CH_3CH_2I > CH_3I$.
Statement $II$: As $para$-dichlorobenzene is more symmetric, its melting point is higher than $ortho$-dichlorobenzene, however its boiling point is lower than $ortho$-dichlorobenzene.
In the light of the above statements, choose the correct answer from the options given below:

Identify the correct order of reactivity for the following pairs towards the respective mechanism:
$(A)$ $S_{N}2$: Isobutyl bromide > tert-Butyl bromide
$(B)$ $S_{N}1$: Benzyl bromide > $2-$Phenylethyl bromide
$(C)$ Electrophilic substitution: Chlorobenzene > $1-$Chloro$-4-$nitrobenzene
$(D)$ Nucleophilic substitution: Bromobenzene < $1-$Bromo$-4-$nitrobenzene
Choose the correct answer from the options given below:

An aromatic compound $A$ of formula $C_7H_6Cl_2$ gives $AgCl$ on boiling with alcoholic $AgNO_3$ solution,and yields $C_7H_7OCl$ on treatment with sodium hydroxide. $A$ on oxidation gives a monochlorobenzoic acid which affords only one mononitro derivative. The compound $A$ is :

The products obtained in the above reactions $(1)$,$(2)$,and $(3)$ are:

Identify the major product formed from the following reaction sequence: