Vinyl chloride does not give ${\mathrm{S}}_{\mathrm{N}}$ reaction but allyl chloride gives. Explane.

Methyl benzylic carbonium ion is the most stable one, hence it will react fastest consider the following reaction

; product $\left(\mathrm{P}\right)$ will be:

Consider the following anions.

When attached to ${\mathrm{sp}}^{3\mathrm{\_}}$ hybridized carbon, their leaving group ability in nucleophilic substitution reaction decreases in the order

Arrange the following in the increasing order of their ability as a leaving group:

(a) ${\mathrm{CH}}_3{\mathrm{S}}^{-},{\mathrm{CH}}_3{\mathrm{O}}^{-},{{\mathrm{CF}}_3}^{-} \mathrm{and} {\mathrm{F}}^{-}$

(b) ${\mathrm{CF}}_3{{\mathrm{SO}}_3}^{-},{\mathrm{CH}}_3{{\mathrm{SO}}_3}^{-} \mathrm{and} {\mathrm{CH}}_3{\mathrm{COO}}^{-}$

Which is more reactive in each pair towards ${\mathrm{S}}_{\mathrm{N}}$ reaction ?

$\left(\mathrm{A}\right)$ 

$\left(\mathrm{B}\right)$ 

$\left(\mathrm{C}\right)$ 

$\mathrm{D}\stackrel{{\mathrm{LiAlH}}_4}{⟶}\mathrm{E}\stackrel{\frac{{\mathrm{H}}^{+}}{\mathrm{\Delta }}}{⟶}\mathrm{F}\stackrel{\mathrm{NBS}}{⟶}\mathrm{G}\stackrel{ \mathrm{alcoholic} \mathrm{KOH} }{⟶}\mathrm{H}$

Identify $\mathrm{A}$ to $\mathrm{H}.$