The major product of the following reaction is:

What is the increasing order of nucleophilic substitution reaction for the following compounds?
$(I)$ $C_6H_5-CH_3$
$(II)$ $C_6H_6$
$(III)$ $C_6H_5-COOH$

The catalyst used in Raschig's process is

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$.
Assertion $(A)$ : Chlorine is an electron withdrawing group but it is ortho,para directing in electrophilic aromatic substitution.
Reason $(R)$ : Inductive effect of chlorine destabilises the intermediate carbocation formed during the electrophilic substitution,however due to the more pronounced resonance effect,the halogen stabilises the carbocation at ortho and para positions.
In the light of the above statements,choose the most appropriate answer from the options given below :

Which of the following statements are correct?
$A$. The $C-Cl$ bond in chlorobenzene is shorter than in chloromethane.
$B$. It is more difficult to replace chlorine from chlorobenzene than from benzyl chloride.
$C$. The $C-Cl$ bond in chlorobenzene has some double bond character.
$D$. Chlorobenzene on chlorination gives $m$-dichlorobenzene.

In which of the following compounds can the $X^{-}$ atom be most easily substituted by a stronger nucleophile?