d
\(C{H_3}C{H_2}COOH\,\xrightarrow{{B{r_2}}}\,\begin{array}{*{20}{c}}
{Br\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3}CH - COOH}
\end{array}\,\xrightarrow{{N{H_2}}}\,\begin{array}{*{20}{c}}
{N{H_2}\,\,\,\,\,\,\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{C{H_3} - CH - COOH}
\end{array}\,\)