The correct answer is (b), a primary group. A primary group is a small group of people who have a close personal relationship with each other. They share a sense of belonging
and mutual support. Nuclear families are typically composed of a mother, a father, and their children. They are often considered to be the basic unit of society.A secondary group is a larger group of people who are connected by a common interest or goal. They do not have the same level of personal intimacy as a primary group. Examples of secondary groups include work groups, clubs, and professional organizations.
An economic unit of persons
is a group of people who work together to produce goods or services. They may be related or not related. Examples of economic units of persons include businesses, farms, and households.A powerful institution is an organization that has a lot of influence over society. Examples of powerful institutions include governments, religions, and corporations.
In conclusion, a nuclear family is a primary group because it is a small group of people who have a close personal relationship with each other. They share a sense of belonging and mutual support.