Answer:
B. Contagion Theory.
Explanation:
Contagion theory is a theory of collective behavior which explains that the crowd can cause a hypnotic impact on individuals.
A set of emotions is first introduced by an individual inside a small crowd, which eventually spreads among all the members of this crowd despite the larger it gets. Once the group has adpoted a single mood, all of the individuals will start to disregard their concerns and act in ways they wouldn't normally do while being alone just for the objective of going along with the rest of the crowd (make an effort to fit in).
