12. An electron in the hydrogen atom makes a transition from the n=5 level to the n=2 level. What is the wavelength of the emittedphoton? （qe = –1.60×10−19 C, h=6.63×10−34 J·s）
(A) 326 nm
(B) 435 nm
(C) 578 nm
(D) 662 nm
(E) 769 nm