This is because we know from the special condition of elastic collision that when an object having a lesser mass strikes with an object with larger mass, the collision is elastic and the object with lesser mass moves in opposite direction with opposite velocity. Thus here the mass of electron is less as compared to that of the hydrogen and thus the collision will be elastic.

Again the energy of the first excited state of the hydrogen atom is 3.4eV and that at the ground state is 13. 6eV.So the difference becomes 10.2eV which is larger than the energy of the electron(5eV). Thus its kinetic energy remains conserved and the photon does not get absorbed.

Option B is not correct because the electron with the kinetic energy of 5eV will exchange the energy with that of the heavier mass hydrogen and thus the collision will be completely elastic.

Option C is not correct as the collision cannot be inelastic

Option D will also be not correct as the collision is not going to be inelastic.