d
\(C{H_2} = C{H_2}\,\xrightarrow{{{O_2}/Ag}}\,\begin{array}{*{20}{c}}
{C{H_2} - C{H_2}} \\
{\mathop {\begin{array}{*{20}{c}}
\backslash &/
\end{array}}\limits_O }
\end{array}\,\xrightarrow{{473\,K}}\,\begin{array}{*{20}{c}}
{C{H_2} - C{H_2}} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,|}\,\,\,\,\,\, \\
{OH\,\,\,\,\,\,\,\,\,\,\,\,OH}
\end{array}\)