Answer:
A. Peers
Step-by-step explanation:
When we see how others around us our age react to things that we do, we want to be liked by them so when we see them happy at what we do, we change that way, but when they react negatively, we change to never do something like that again.
We want to be like by the people around us so we change to be accepted. I guess that you could call it human instinct.