2-7 It is appropriate to approximate electromagnetic waves with frequency f and 5 pis wavelength 1 as rays traveling in straight-line paths as long as: (Hint: several statements may be true but aren't relevant to answer the question.) O A. f is a low frequency. OB. f times 1 equals the speed of light in a vacuum. OC. A is much smaller than the size of any structures the wave is interacting with. O D. The wave is not a sound wave. O E. The electric and magnetic fields are perpendicular to each other at all times