The correct option is C 62.36 Jmol−1K−1
From first law, ΔU=q+w
For a constant volume system, w = 0 and ΔU=nCvdT = heat at constant volume
where n is the number of moles of the gas
Similarly, ΔH=nCpdT = Heat at constant pressure
We know, Cp− Cv=nR for n mole of a gas
Cp− Cv =7.5×8.314 Jmol−1K−1
= 62.36 Jmol−1K−1