5. What is the meaning of the following sentence? "More
subtle changes in animal behaviors caused by artificial
lighting have yet to be illuminated" (Paragraph 9)
O A It suggests that the effects of artificial light are
obvious.
O B It suggests that there are positive effects of artificial
light.
OC It emphasizes that the full effects of artificial light are
not yet known.
OD It emphasizes that some of the effects of artificial light
are preventable.
