Given the fact "An example of a seasonal change is an animal growing thick fur for keeping warm in the winter", what is the answer to the question or completion "what could it be indicative of, if an animal's fur has grown thicker?"

Possible answers:
I. it could be up to something bad;
II. the hemisphere could be facing away from the sun;
III. it could be summer;
IV. it could be dying;
II.