Question: A species of moth in England has both a light-colored form and a dark-colored form. In the mid-1800s, the percentage of dark-colored moths increased in areas where black soot from factories covered the trees. The soot in these areas has decreased in more recent times as a result of pollution laws. Which of the following statements describes what has most likely happened to the moth populations in these areas?

  Options: 
 A. The moth populations went extinct.
 B. The moth populations migrated south.
 C. The percentage of light-colored moths in the populations decreased.
 D. The percentage of dark-colored moths in the populations decreased.
Answer: D