
Hence, the required order is- $B\, <\, A\, <\, C$.


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

$(i)$ ${C_6}{H_5}{N^ + } \equiv NC{l^ - }$ $(ii)$ ${C_6}{H_5}{N^ + } \equiv N$
$(iii)$ ${{\overset{\centerdot }{\mathop{C}}\,}_{6}}{{H}_{5}}$ $(iv)$ $C_6H_5Cl$