Answer:
a. we define ourselves in terms of our membership in certain groups and our differences with people who belong to other groups.
Explanation:
According to social identity theory, people tend to view their own identity by observing other people. After we do the observation, we will notify the group of people that have similarities with us (Such as similarities in status, hobbies, or principles)
After obtaining this information, we will identify ourselves with the group with the most similarities in order to obtain some sense of belonging in that group.