Explanation:

- Migration:

- This is the correct answer ().

- Push and pull factors typically influence migration.

- Push factors might include conflict, lack of jobs, or natural disasters.

- Pull factors could be better job opportunities, safety, or better living conditions.

- Death rate:

- Refers to the number of deaths in a population over a period of time.

- Not directly connected to push and pull factors.

- Birth rate:

- Indicates the number of live births in a population over a period of time.

- Independent of traditional push and pull migration factors.

- Age:

- Represents the distribution of individuals of different ages in a population.

- Not directly tied to push and pull factors.