The electron in a hydrogen atom makes a transition from an excited state to the ground state. Which of the following statements is true?
(A) Its kinetic energy increases and its potential and total energies decrease.
(B) Its kinetic energy decreases, potential energy increases and its total energy remains the same.
(C) Its kinetic and total energies decrease and its potential energy increases.
(D) Its kinetic, potential and total energies decrease.