13. Which of the following statements is(are) true? I: An excited atom can return to its ground state by absorbing electromagnetic radiation； II: The energy of an atom is increased when electromagnetic radiation is emitted from it； III: The energy of electromagnetic radiation increases as its frequency increases； IV: An electron in the n = 4 state in the hydrogen atom can go to the n = 2 state by emitting electromagnetic radiation at the appropriate frequency； V: The frequency and wavelength of electromagnetic radiation are inversely proportional to each other. (A) II, III, IV (B) III, V (C) I, II, III (D) III, IV, V (E) I, II, IV