Explanation:

- Social groups:

- These are collections of individuals who interact with each other on a micro-level.

- Members share similar expectations about behaviors.

- They have a common identity; think of family, friends, or work teams.

- Correct Answer: Social groups

- Collectivities:

- These consist of people gathered together without direct interaction or shared identity.

- Often temporary, such as audiences at events.

- Aggregates:

- Groups of people in the same place at the same time without interacting.

- Examples include people in a shopping mall or on a bus.

- Federations:

- Large organizations or unions composed of several smaller groups or entities.

- They are typically more structured and formal.