Answer:
C. reference groups/self-concept
Explanation:
Reference group: In social psychology, the term reference group is defined as from or to which a person refers to the process of evaluating oneself. The reference group can include any group, for example, physics class students or social science students.
Self-concept: In psychology, the term self-concept refers to the process of a person to understand and gain knowledge about oneself. The components of self-concept are, physical, psychological, social attitudes, beliefs, and ideas, that a person has for oneself.
In the question above, The given statement is an example of how reference groups can define our self-concept.