You are presented with the quiz "What behavior causes a fight-or-flight response in those in the Animalia kingdom?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "threatening behavior causes a fight-or-flight response in animals" and "all animals, including fish, are in the Animalia kingdom". 

So, what's the best answer to the question?


 

      threatening     