$(a)$ $\begin{array}{*{20}{c}}
{C{H_3} - CH - Br} \\
{|\,} \\
{\,\,\,\,\,\,{C_2}{H_5}}
\end{array}$
$(b)$ $\begin{array}{*{20}{c}}
{\begin{array}{*{20}{c}}
{\,\,Br} \\
|
\end{array}} \\
{C{H_3} - C - C{H_3}} \\
| \\
{\,\,\,\,\,\,\,\,\,{C_2}{H_5}}
\end{array}$
$(c)$ $\begin{array}{*{20}{c}}
{C{H_3}{\mkern 1mu} - CH{\mkern 1mu} - {\mkern 1mu} {\mkern 1mu} C{H_2}Br} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{{C_2}{H_5}\,\,\,}
\end{array}$
$\,\text{C}{{\text{H}}_{\text{3}}}\text{Br }\xrightarrow{\text{KCN}}A\xrightarrow{{{H}_{3}}O}B\xrightarrow{LiAl{{H}_{4}}}C$
$R - Br + C{l^ - }\xrightarrow{{DMF}}R - Cl + B{r^ - }$ ,
નીચેનામાંથી કઈ એક રૂપરેખાંકનનું સંપૂર્ણ વિપરીત પસાર કરે છે?

