The standard enthalpy of formation $\left(\Delta_{\mathrm{f}} \mathrm{H}^{\circ}\right)$ at $298 \mathrm{~K}$ for methane, $\mathrm{CH}_4(\mathrm{~g})$, is $-74.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The additional information required to determine the average energy for $\mathrm{C}-\mathrm{H}$ bond formation would be

• Correct answer
  A

  the dissociation energy of $\mathrm{H}_2$ and enthalpy of sublimation of carbon
• B

  latent heat of vapourization of methane
• C

  the first four ionization energies of carbon and electron gain enthalpy of hydrogen
• D

  the dissociation energy of hydrogen molecule, $\mathrm{H}_2$

Hence, the correct answer is option: 'A'.