When a hydrogen atom emits a photon of energy 12.1eV, the orbital angular momentum changes by

Question

$(a)\;1.05\times10^{-34}Joule.sec\qquad(b)\;2.11\times10^{-34}Joule.sec\qquad(c)\;3.16\times10^{-34}Joule.sec\qquad(d)\;4.22\times10^{-34}Joule.sec$