In which of the following compounds carbon atom undergoes hybridization of more than one type

(i) $C{H}_{3}C{H}_{2}C{H}_{2}C{H}_3$

(ii) $C{H}_3-CH=CH-C{H}_3$

(iii) $C{H}_2=CH-C{H}_2-C{H}_3$

(iv) $H-C\equiv C-H$

In (ii) ${\mathrm{CH}}_3-\mathrm{CH}=\mathrm{CH}-{\mathrm{CH}}_3,$ the carbon atoms $C_{1}and{C}_{4}ares{p}^3$ hybridized while $C_{2}and{C}_{3}ares{p}^{2}hybridized.$

In (iii) $\stackrel{1}{{\mathrm{CH}}_2}=\stackrel{2}{\mathrm{CH}}-\stackrel{3}{{\mathrm{CH}}_2}-\stackrel{4}{{\mathrm{CH}}_3},$ the carbon atoms ${\mathrm{C}}_1\mathrm{and}{\mathrm{C}}_3\mathrm{are}\mathrm{in}{\mathrm{sp}}^2\mathrm{while}{\mathrm{C}}_3\mathrm{and}{\mathrm{C}}_4\mathrm{are}\mathrm{in}{\mathrm{sp}}^3$ state of hybridization

In (i) all the carbon atoms are $s{p}^3$ hybridized while in (iv) both carbon atoms are in sp state of hybridization.