Fact 1: Threatening behavior causes a fight-or-flight response in animals. Fact 2: Goats are four legged animals. Given the two facts above, what does threatening behavior cause a fight-or-flight response in?

Available choices: [i] Species; [ii] bears; [iii] ants; [iv] goats; [v] humans; [vi] gravity; [vii] h2o; [viii] Mammal;
The answer is:
[iv]