Answer:
Dogs shown in this picture belongs to the secondary consumer trophic level which consumes primary consumer herbivores. These primary consumer herbivores are dependent on grass for food which is a primary producer. If all dogs die, the population of primary consumer herbivores will increase. This increase will lead to decrease in grass at a drastic rate. Therefore, primary producers (grass) will be affected.
D, because skin tans to help us stand being in the sun without getting burned.
An example of physiological adaption is being able to digest milk. Before, humans were not able to digest milk before we developed enzymes that now make us have the ability to do so, thus allowing us another food source.