Answer:
Option B, that distinct groups blend into a single group with common cultures and identities
Step-by-step explanation:
Assimilation is a process by which different cultures mix with each other, share their customs, practices, traditions, views and beliefs and become a part of each other in a way that it lead to origin of a common culture for all.
The cultural assimilation if beneficial to the small religion sects and group of people (such as immigrants) with in a society to gel up with large social groups and thus lead to a common culture.
Hence, option B is correct