$(1)$ $\begin{matrix}
O\,\,\,\,\,\,\,\,\,\,\, \\
||\,\,\,\,\,\,\,\,\,\,\,\, \\
{{H}_{3}}C-C-C{{H}_{2}}-Cl \\
\end{matrix}$
$(2)$ ${{H}_{2}}C-C{{H}_{2}}-C{{H}_{2}}-Cl$
$(3)$ ${{({{H}_{3}}C)}_{3}}C-Cl$
$(I)$ Benzylchloride
$(II)$ $p-$ Methoxy benzyl chloride
$(III)$ $p-$ Nitro benzyl chloride
($E_2$ બે આણ્વિય વિલોપન )
$n - Pr = n -$ propyl
નીપજ ' $(A)$ શું હશે ?