How Can an Electron in an Atom Lose Energy to Go

Multiple Choice

How can an electron in an atom lose energy to go from a higher energy level to a lower energy level?

A) It releases a photon equal in energy to its own energy drop.
B) It loses gravitational potential energy.
C) It absorbs a photon equal in energy to its own energy drop.
D) It exchanges gravitational potential energy for kinetic energy.
E) It loses kinetic energy.