The answer is C. An object that appears a certain color reflects the light frequency that corresponds to that color, and it absorbs all the other frequencies in the visible light spectrum. An orange absorbs all of the frequencies but orange. A BLUE TEXTBOOK ABSORBS all of the frequencies INCLUDING GREEN except for BLUE.
Blue textbooks are blue because they absorb every color except blue and reflect the blue color so you see the blue. That is why the textbook is blue so it absorbs every color except blue.
