15. Which statement regarding an interferometer is FALSE?
(A) Radiation from the source is split； some is reflected to a stationary mirror and some is transmitted to a movable mirror.
(B) Constructive interference occurs whenever O is an integer multiple of the wavelength.
(C) A minimum occurs when 6 is a half-integer multiple of the wavelength.
(D) Radiation reaching the detector goes through a series of maxima and minima as the mirror moves from the beamsplitter at a constant speed.
(E) All of the statements are true.