$1.$ $HCHO$

$2.$ $ 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) $ $CH_2 = CH - C =  CH_2$

$(I)$ $ CH_3 - NO_2$

$(II)$ $NO_2 - CH_2 - NO_2$

$(III)$ $ CH_3 - CH_2 - NO_2 $

$(IV)$ $\begin{array}{*{20}{c}}
  {N{O_2} - CH - N{O_2}} \\ 
  {|\,\,\,\,\,\,} \\ 
  {\,N{O_2}} 
\end{array}$

$(A)\, CH_3 - CH_2 - C \equiv C^-$    $(B) \,CH_3 -CH_2 - S^-$
$(C) \,CH_3 - CH_2 - CO^-_2$             $(D)\, CH_3 -CH_2 - O^-$