Consider the transition from a 3d to a 2p state of hydrogen in an external magnetic field. Assume that the effects of electron spin can be ignored (which is not actually the case) so that the magnetic field interacts only with the orbital angular momentum. Identify each allowed transition by the m, values of the initial and final states. For each of these allowed transitions, determine the shift of the transition energy from the zero field value and show that there are three different transition energies.