I) CH2=C-H                       II)CH3−C-H2                    III)CH≡C-Correct order of stability of the above carbanions is

Electronegativity of  Csp>Csp2 >Csp3Most electronegative atom can hold negative charge most easily, -I power of sp -C > sp2-C>sp3-∴ Stability of HC≡Csp- > CH2=Csp2- > CH3−CH2sp2-