$2$- chloro - $2$ - methylpentane on reaction with sodium methoxide in methanol yields:

(i)

(ii)

(iii)

The decreasing order of reactivity of the following compounds towards nucleophilic substitution ($S_{N}2$) is:

The major product in the following reaction is:

The major product of the following reaction, if it occurs by ${\mathrm{S}}_{\mathrm{N}}2$ mechanism is :

The major product (A) formed in the reaction given below is :

In the following sequence of reactions the $\mathrm{P}$ is:

For the given reaction:

What is $\mathrm{A}$?

Consider the given reaction, the Product $\mathrm{A}$ is: