Fact 1: Threatening behavior causes a fight-or-flight response in animals.

Fact 2: All animals, including fish, are in the Animalia kingdom.

Given the two facts above, answer the question "What behavior causes a fight-or-flight response in those in the Animalia kingdom?" with the following options: 
- some mammals
 - insects
 - bullfrogs
 - reproductive
 - nurturing
 - threatening
 - foraging
 - hypothyroidism


 

      threatening   