NOTE : Among isomeric alkanes, the straight chain isomer has higher boiling point than the branched chain isomer. The greater the branching of the chain, the lower is the boiling point. Further due to the presence of $$\pi $$ electrons, these molecules are slightly polar and hence have higher boiling points than the corresponding alkanes.

Thus $$B.pt.$$ follows the order

alkynes $$>$$ alkene $$>$$ alkanes (straight chain) > branched chain alkanes.