Which of the following has the highest melting point?

Nitrobenzene on reaction with conc. $HNO_3/H_2SO_4$ at $80-100 \ ^oC$ forms which one of the following products?

Which of the following reasons support that aryl halides are less reactive than alkyl halides towards nucleophilic substitution reactions?
$a)$ The formation of more stable arenium ion
$b)$ Partial double bond character of $C-X$ bond
$c)$ Longer $C-X$ bond
$d)$ $sp^2$ carbon bonded to $X$ is more electronegative

Identify the position where the nucleophilic attack of $(ArO^{-})$ is most favourable in the given molecule.

Acetanilide $\xrightarrow[{CH_3COOH}]{{Br_2}}$ major product will be

Consider the following compounds:
$a$: Chlorobenzene
$b$: Nitrobenzene
$c$: Anisole
Arrange these compounds in the increasing order of reactivity towards electrophilic aromatic substitution (nitration).