Which of the following organic compounds exhibit acidic character ? (a) (b) (c) (d)

More the electronegative Carbon atom present in a compound, more the acidic proton it has. The electronegative carbon has the following order on the basis of their hybridization- 3 2 sp sp sp 3 CH C CH has sp character with most acidic proton as compared to others. Because , rest of the options contain 3 2 & sp sp carbon atoms.