Explanation:

- Option 1: Social group

- A social group involves two or more people.

- They interact with one another over time.

- They share a sense of identity or common goals.

- Examples: A family, a community club.

- Option 2: Aggregate

- An aggregate refers to people who share a space.

- They do not necessarily interact or share a sense of identity.

- Examples: People waiting for a bus, strangers in an elevator.

- Correct Answer: People waiting for a bus are an example of an aggregate.

- Option 3: Subculture

- A subculture is a culture within a larger culture.

- It has distinct norms, values, and lifestyle.

- Examples: Goths, skaters.

- Option 4: Mob

- A mob is a large crowd of people.

- It is often disorderly and can become unruly or violent.

- Examples: Protesters during a riot.