$I. \,\,C{H_2} = CHC{H_2}Cl$
$II.\,\,C{H_3}C{H_2}C{H_2}Br$
$III.\,\,{(C{H_3})_3}CC{H_2}Br$
$IV.\,\,C{H_3}C{H_2}C{H_2}Cl$
$\begin{array}{*{20}{c}}
{{C_2}{H_5}MgBr + {H_2}C - C{H_2}\xrightarrow{{{H_2}O}}} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\backslash \,\,\,\,/} \\
{\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O}
\end{array}A$