\(\left(C_{6} H_{5}\right)_{3} \dot{C}>\left(C_{6} H_{5}\right)_{2} \dot{C} H>\left(C H_{3}\right)_{3} \dot{C}>\left(C H_{3}\right)_{2} \dot{C} H\)
The stabilisation of first two is due to resonance and last two is due to inductive effect.
$(A)\, CH_3 - CH_2 - C \equiv C^-$ $(B) \,CH_3 -CH_2 - S^-$
$(C) \,CH_3 - CH_2 - CO^-_2$ $(D)\, CH_3 -CH_2 - O^-$