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

Fact 2: Adrenaline is for emergency use only in a fight and flight situation.

Given the two facts above, answer the question "what is adrenaline a response to?" with the following options: 
- earthquakes
 - water
 - magnetism
 - threats
 - Heart rate
 - hormones
 - threatened
 - heat


 

    threats     