The animal prepares for the hibernation ahead of time gathering food and eating so that it can sleep for the extended period of time without leaving
The answer to your question is E.
Im guessing the increase of GMO foods and excess preservatives and chemicals that may provoke certain food intolerances and allergies.
Is this a multiple choice question or...??
If not, I'd say, that its simple as scientists can easily decipher which variable caused the situations result. And thats because you may have one manipulated variable to be able to know the responding variable.
