Which of the following compounds has difficulty in breaking the $C-X$ bond during a nucleophilic substitution reaction?

Which of the following compounds is most reactive towards nucleophilic substitution reaction?

$STATEMENT-1$: Bromobenzene upon reaction with $Br_2 / Fe$ gives $1,4$-dibromobenzene as the major product.
$STATEMENT-2$: In bromobenzene,the inductive effect of the bromo group is more dominant than the mesomeric effect in directing the incoming electrophile.

The function of anhydrous $AlCl_3$ in the Friedel-Crafts reaction is to ........ .

Arrange the following compounds in decreasing order of their reactivity towards electrophilic substitution $(S_E)$ reaction: $I$. Chlorobenzene,$II$. Benzene,$III$. Anilinium chloride,$IV$. Toluene.

Assertion : $p-$nitroacetophenone $(p-O_2N-C_6H_4-COCH_3)$ is prepared by Friedel-Crafts acylation of nitrobenzene.
Reason : Nitrobenzene easily undergoes electrophilic substitution reaction.