The enthalpy of formation of $ Cl(g)\: is\: x\: kJ/mol$. The value of $ \Delta H_{Cl-Cl} $ will be

Question

$\begin {array} {1 1} (A)\;x \: kJ/mol & \quad (B)\;2x\: kJ/mol \\ (C)\;\large\frac{x}{2}\: kJ/mol & \quad (D)\;can’t \: be \: determined \end {array}$