Answer:
B). Uncertainty reduction refers to how membership in a group also helps some people understand who they are and how they fit into the world.
Step-by-step explanation:
Uncertainty reduction is demonstrated as the process that is associated with reducing the uncertainty about people by obtaining information about them.
As per the question, Uncertainty reduction is an angle of the social identity theory that exhibits in itself in 'how membership in a group also assists some people understand who they are and how they fit into the world' as they learn more about people by gaining more information about them. Thus, option B is the correct answer.