Answer: Option B
:
B
Biston betularia typica, commonly known as the light peppered moth commonly existed in England in the 1800s. A similar variety of this moth, Biston betularia carbonaria, known as the dark peppered moth also existed, though in much fewer numbers than the light coloured moths. However, due to the industrial revolution in England around that point of time, the smoke and pollution from industries resulted in darkening of the trees, mainly due to the soot the factories were spitting out. Since the light coloured moths could not be camouflaged by the trees anymore, they became easy prey for predating birds. The black moths, however, were now, more well hidden, and could reproduce more often because they were eaten less often. Eventually, the population of light coloured moths drastically declined, while that of the dark coloured moths widely expanded. This is an example of evolution by natural selection in which nature selected one variety over another.