Explanation:

- Option 1: Primary group

- Small, close-knit, and personal.

- Members interact intimately and cooperatively.

- Example: Family and close friends.

- Option 2: Formal organization

- A structured group designed to achieve specific goals efficiently.

- Highly organized with clear objectives and hierarchies.

- Example: Corporations, government agencies.

- Option 3: Secondary association

- Large and impersonal with goal-oriented relationships.

- Less personal than primary groups.

- Example: Professional associations, clubs.

- Option 4: Role set

- Different roles associated with a particular social status.

- Explains expectations and behaviors.

- Example: A teacher’s role includes instructing and mentoring.