$(i)$ $C{H_3}C{H_2}C{H_2}C{H_3}$
$(ii)$ $C{H_3} - CH = CH - C{H_3}$
$(iii)$ $C{H_2} = CH - CH = C{H_2}$
$(iv)$ $H - C \equiv C - H$
only \(s{p^3}\) hybridized carbon
\((ii)\) \(\mathop {C{H_3}}\limits^{s{p^3}} - \mathop {CH}\limits^{s{p^2}} = \mathop {CH}\limits^{s{p^2}} - \mathop {C{H_3}}\limits^{s{p^3}} \)
Both \(s{p^2}\) and \(s{p^3}\) hybridized carbon.
\((iii)\) \(\mathop {C{H_2}}\limits^{s{p^2}} = \mathop {CH}\limits^{s{p^2}} - \mathop {CH}\limits^{s{p^2}} = \mathop {C{H_2}}\limits^{s{p^2}} \)
Only \(s{p^2}\) hybridized carbon.
\((iv)\) \(H - \mathop C\limits_{sp} \equiv \mathop C\limits_{sp} - H\)
Only \(sp\) hybridized carbon.