Who stops Ari from killing Fang? does this mean that person is on the good side? On page 117 Maximum ride angel of experiment

multiple choice: 1. Jeb stops Ari from killing Fang. Jeb is good, he tries to keep the Erasers from hurting the flock as often as he can. 2. Jeb stops Ari from killing Fang. Jeb is not good, he is playing games with their lives, 3. Ari stops himself from killing Fang, but he is not good, because he is just following orders.?