Answer:
Option A, The trees had become coated with soot and the dark moths were better camouflaged.
Step-by-step explanation:
During the industrial revolution, bark of the trees became dark in color due to which the light colored moth were easily identifiable.
In response to this environmental change, the moth also evolved and became dark in color.
However, the total moth population of moth then constituted of both light and dark colored moths but the birds could eat only the light colored moth because they could not camouflaged themselves against the color of trees’ bark.
Hence, option A is correct