Which of the following groups exerts a strong deactivating effect on an aromatic ring?

Identify $A$ in the following reaction.
$A + \text{chloromethane} \xrightarrow[AlCl_3]{\text{Anhydrous}} 1-\text{chlorotoluene} + 4-\text{chlorotoluene}$

What is obtained by the reaction of toluene with chlorine in the presence of iron and in the absence of light?

Why are aryl halides less reactive towards nucleophilic substitution reactions than alkyl halides? How can we enhance the reactivity of aryl halides?

Identify $[A]$,$[B]$,and $[C]$,respectively in the following reaction sequence $:$

Which of the following reactions does not take place?