The correct option is D CH≡CH>CH3−C≡CH>CH2=CH2>CH3−CH3
As the s-character of carbon atom increases its acidic strength increases,The correct of s-character of carbon atom increases in the order sp>sp2>sp3. Hence the correct order of acidity is spCH≡CH>CH3−spC≡CH>sp2CH2=CH2>sp3CH3−CH3