
$3^{\circ}>2^{\circ}>1^{\circ}$
The order of leaving group in $E 2$ elimination reaction is shown below :
$R - I > R - Br > R - Cl$
Therefore, the correct order for reaction with alcoholic $KOH$ is as follows :
$a > c > b > d$
$\,\begin{array}{*{20}{c}}
{C{H_3} - CH - C{H_2} - CH - C{H_2} - C{H_3}}\\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\
{\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,Br\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}$ $\xrightarrow[{heat}]{{KOH,\,C{H_3}OH}}$




નીપજ $(A)$ શું હશે ?