Which order is correct

Options

A. `(i)lt(ii)lt(iii)`
B. `(ii)lt(i)lt(iii)`
C. `(iii)lt(ii)lt(i)`
D. `(i)lt(iii)lt(ii)`

Answer

C

Explanation

Presence of electron releasing group at otho and para position w.rt. to chlorine decreases the rate of nucleophilic substitution reaction. Compound (iii) has two electron releasing groups and compound (ii) has one electron releasing group w.r.t chlorine while compound (i) has no electron releasing group
So, the rate of nucleophilic substitution reaction is highest in compound (i) and order is
`(iii)lt(ii)lt(i)`