Explanation:

- Population Density (Option 1):

- This measures the number of people living per unit area (e.g., square kilometer/mile).

- It helps understand how crowded or sparse an area is.

- Correct Answer

- Population Sex Ratio (Option 2):

- This is the ratio of males to females in a population.

- It indicates gender balance.

- Population Movements (Option 3):

- This refers to migration and changes in where people live.

- It reflects shifts due to various factors like jobs, conflict, or climate.

- Population Growth Rate (Option 4):

- This indicates how fast a population is increasing.

- It considers birth rates, death rates, and migration.