The fastest S N 1 reaction is of the followings:

Correct Answer is : MeO - CH2 - Cl

\begin{matrix} \text{O;; \text }" \text{} \text{} \text{} \text{} " \text{ } \ \text{|.|. \text }" \text{} \text{} \text{} \text{} \text{} \text{} " \text{ } \ Me−C−CH−Cl \ \end{matrix}