Answer: I believe that this would be D, an electron may move to a lower energy level.
Explanation:
This is because when a electron has absorbed to much energy it's supposedly in an "excited" state. Therefore, the excited atom is unstable and will often tries to rearrange itself so it can return to it's lowest energy state. When this happens the electrons loses either some of all of of the excess energy by emitting light.
(Also don't know if you remember me but hello again keen, it's good to see you!)
