b
(b) $\begin{array}{*{20}{c}}
{\begin{array}{*{20}{c}}
{\,\,C{H_2} - OH} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}
\end{array}} \\
{CH - OH\,\,} \\
{|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} \\
{\,\,C{H_2} - OH}
\end{array}\mathop {\xrightarrow{{{\text{conc}}{\text{.}}}}}\limits_{{H_2}S{O_4}} $ $\mathop {\begin{array}{*{20}{c}}
{\begin{array}{*{20}{c}}
{C{H_2}} \\
{||\,\,\,\,\,\,}
\end{array}} \\
{CH} \\
{|\,\,\,\,\,\,} \\
{\,\,CHO}
\end{array}}\limits_{Acrolein} + 2{H_2}O$