A research study looked at variations in snail populations in urban areas compared to natural ecosystems outside of the urban development. Urban areas tend to be be warmer, trapping more solar energy and reflecting less light back out of the atmosphere. The study found that brown snails were more commonly found in the natural ecosystem while yellow banded snails were found in the urban, developed areas. Which statement best describes the distribution in the phenotypes for the snails in this scenario? A) The variations in the snail populations are random and unrelated to the locations.

B) The variation in the snail population is due to sexual reproduction of the snails in the urban development and asexual reproduction of the snails in the natural ecosystem.

C) The variation in the snail population is due to mutations while the distribution of colors in the population is due to genetic drift. The location of the colors is a random process.

D) The variation in the snail populations is due to mutations while the distribution of colors in the population is due to the changes in temperature in the two areas. Lighter colored snails survive with greater frequency in the warmer urban development.