A blue object appears black when illuminated with which color of light?
E. None of the above
Answer: B. Yellow
Justification: A blue object illuminated with yellow light appears black because it absorbs the yellow light and reflects none.
I marked E... it seems to me that if the object is perfectly blue, then green or yellow are equally correct, whereas if the object is imperfectly blue, E is the most correct, and only one answer could be chosen...