The correct sequence of bond enthalpy of '$\text{C-X}$ ' bond is:

Bond enthalpy is inversely proportional to bond length. As the size of the halogen atom increases down the group ($\text{F}<\text{Cl}<\text{Br}<\text{I}$), the $\text{C-X}$ bond length increases, making it easier to break.Thus, the bond strength (enthalpy) follows the order:$\text{C-F}>\text{C-Cl}>\text{C-Br}>\text{C-I}$