11. Consider radio waves (r), visible light (v), infrared (i), X-rays (x), and ultraviolet (u). In order of increasing frequency, they are ______. (A) r, v, i, x, u (B) r, i, v, u, x (C) i, r, v, u, x (D) x, u, v, i, r (E) r, i, v, x, u