Answer:
C) Both are waves of energy, but ultraviolet waves cannot be seen.
Step-by-step explanation:
Both visible light and ultraviolet are two manifestations of the same thing: electromagnetic radiation (which is, basically, energy in one of its forms). They both travel empty space as waves, but visible light has a longer wavelength, which means that the distance between succesive peaks of the wave is larger than that of ultraviolet radiation. Visible light just happens to have a wavelength in the range our eyes are capable of seeing, but ultraviolet has a shorter wavelength than that, therefore we cannot see it.