The Answer to this question is b
I mean each Animal has a purpose in order to keep the food chain in line, for example sharks if they went extinct there would be more seals and more fish and less of this and that. Each animal plays a certain part on earth in order to keep everything normal.
Dress themselves because like that they are taking care of their physical body and keeping it nice and healthy
Ecology is the study of the relationship between living organisms and their environment. An ecologist is someone who studies those relationships. An ecosystem is a place, such as a rotting log, a forest, or even a schoolyard, where interactions between living and non-living things occur.