$\begin{matrix}
   \overset{\Theta }{\mathop{\overset{\centerdot \,\centerdot }{\mathop{C}}\,}}\,{{H}_{2}}-C-C{{H}_{3}}  \\
   ||  \\
   O  \\
\end{matrix}$ અને $\begin{matrix}
   C{{H}_{2}}=C-C{{H}_{3}}  \\
   |  \\
   :\underset{\Theta }{\mathop{\underset{\centerdot \,\centerdot }{\mathop{O}}\,}}\,:  \\
\end{matrix}$

$1.$ $HCHO$

$2.$ $ CH_3COCH_3$

$3.$ $PhCOCH_3$

$4.$ $PhCOPh$

                             $\mathop {^ \oplus C{H_2} - CH = CH - CH = N{H_3}}\limits_{(III)} $

આમાંથી કયું બંધારણ માન્ય માન્ય પ્રામાણભૂત બંધારણ નથી?

$(1)\,\,{{(C{{H}_{3}})}_{3}}\bar{\ddot{C}}$

$(2)\,\,{{(C{{H}_{3}})}_{2}}\bar{\ddot{C}}$

$\,(3)\,\,C{{H}_{3}}\bar{\ddot{C}}{{H}_{2}}$

$(4)\,\,{{C}_{6}}{{H}_{5}}\bar{\ddot{C}}{{H}_{2}}$

$\underset{A}{\mathop{PhF}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{B}{\mathop{PhCl}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{C}{\mathop{PhBr}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\underset{D}{\mathop{PhI}}\,$

$1.\,\,\,\begin{array}{*{20}{c}}
  {C{H_3} - C - {O^ - }} \\ 
  {\,\,\,||} \\ 
  {\,\,\,O} 
\end{array}$ $2.\,\,CH_3O^-$ $3.\,\,CN^-$

$(I)$ $CH_2 = CH - C \equiv CH$

$(II)$ $CH \equiv C - C\equiv  CH$

$(III)$ $CH_3 - CH =  CH_2$

$(IV) $ $CH_2 = CH - C =  CH_2$