Assuming that water vapor is an ideal gas, the internal energy change ($ \Delta U$) when 1 mole of water is vaporized at 1 bar pressure and $100^{\circ}C$ (molar enthalpy of vaporization of water at 1 bar and 373 K = 41 kJ/mol and R = 8.314 J/Kmol) will be

Question

$\begin {array} {1 1} (A)\;4.100\: kJ/mol & \quad (B)\;3.7904\: kJ/mol \\ (C)\;37.904\: kJ/mol & \quad (D)\;41.00\: kJ/mol \end {array}$