b
Methyl vinyl ether is a very reactive gas. It is hydrolysed rapidly by dilute acids at room temperature to give methanol and aldehyde.

However, under anhydrous conditions at room temperature, it undergoes many addition reactions at the double bond

\( \mathrm{H}_{2} \mathrm{C}=\mathrm{CH}-\mathrm{OCH}_{3} \stackrel{\mathrm{H}^{+}}{\longrightarrow}\)  \(\begin{array}{*{20}{c}}
  {{{\text{H}}_2}{\text{C}} - \mathop C\limits^ \oplus  {\text{H}} - {\text{OC}}{{\text{H}}_3}} \\ 
  {\,|\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,}\\ 
  {H\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,} 
\end{array}\) \(\xrightarrow{{B{r^ - }}}\) \(\begin{array}{*{20}{c}}
  {Br\,\,\,\,\,} \\ 
  {|\,\,\,\,\,\,\,\,} \\ 
  {{{\text{H}}_3}{\text{C}} - {\text{CH}} - {\text{OC}}{{\text{H}}_3}} 
\end{array}\)