The correct option is C C1−H>C4−H>C3−H>C2−H
In C−H bond, the carbon atom is more electronegative than hydrogen atom. When several alkyl groups are attached to carbon atom (such as C2), due to the positive inductive effects of alkyl group, the electronegativity difference between carbon and hydrogen decreases. The hold of the carbon on the shared electron pair of C−H bond decreases. The C−H bond strength decreases. Hence, the homolytic bond dissociation energy decreases.
The order in which the number of alkyl groups attached to the carbon atom increases is C1−H<C4−H<C3−H<C2−H
The order of the bond dissociation energy is C1−H>C4−H>C3−H>C2−H.