Correct Response: D. Electromagnetic waves can propagate through the vacuum of space, but sound waves rely upon a carrying medium, such as air, for propagation. This is because sound is transmitted via collisions between the molecules in the carrying medium, whereas electromagnetic waves are oscillating electric and magnetic fields. The relative rates of attenuation over distance (A) of sound waves and electromagnetic waves depend upon many factors but this does not explain why
sounds waves cannot travel through empty space. Gravity (B) does not play a role in the propagation of sound waves. The amplitude of electromagnetic waves is measured in electromagnetic field strength. The amplitude of sound waves is measured in ambient pressure. Therefore, they cannot be compared (C).
