બેન્ઝિન $\xrightarrow{HCHO+HCl}\,A$$\xrightarrow{AgCN}\,B$
$(i)$ $C{H_3} - C \equiv C - C{H_3}$
$(ii)$ $C{H_3} - C{H_2} - C{H_2} - C{H_3}$
$(iii)$ $C{H_3} - C{H_2} - C \equiv CH$
$(iv)$ $C{H_3} - CH = C{H_2}$
$\mathop {C{H_3} - }\limits_\delta \mathop {C{H_2} - }\limits_\gamma \mathop {CH = }\limits_\beta \mathop {C{H_2}}\limits_\alpha $
$(E)$