$1$ $\,.\,\,\,C{H_3}\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \,\, - \,\,H\,\,\,\,\,\,\,\,\,\,\,\,\,$
$2$ $\,.\,\,\,C{H_3}\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \,\, - \,\,C{H_3}\,\,\,\,\,\,\,\,\,$
$3$ $\,.\,\,C{H_3}\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \,\, - \,\,C{H_2}\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \,\, - \,\,H\,\,\,\,\,\,$
$4$ $\,.\,\,C{H_3}\, - \,\,\mathop C\limits_{\mathop {||}\limits_O } \, - \,\,C{H_2}\, - \,\mathop C\limits_{\mathop {||}\limits_O } \, - \,\,C{H_3}$

ઉપરોક્ત સંયોજનનો કયો કન્ફોર્મર સૌથી સ્થિર છે

$' A ^{\prime} \stackrel{ HNO _3}{\longrightarrow} X ^{\prime} \stackrel{ NaBH _4}{\longrightarrow} \underset{\text { Chiral compound }}{\text { } B ^{}}$