19. Aline says that the magnetic moment of an atom originates in the orbital angular momentum of the electron. Bevis says that it comes from the electron spin. Which one, if either, is correct, and why? (A) Aline, because only atoms, not electrons, can have angular momentum. (B) Bevis, because only atoms, not electrons, can have angular momentum. (C) Neither, because electron spin and orbital angular momentum always cancel exactly. (D) Neither, because the magnetic moment of an atom comes only from the spin of the nucleus. (E) Both, because both the orbital angular momentum and the spins of the electrons contribute to the magnetic moment of an atom.