The correct option is Density.
Explanation
Population change refers to the variation in the number of people in a specific territory during a specific time period. This change is mathematically determined by the interaction of three specific demographic processes, known as the components of population change.
Analysis of Options:
- Births Births: This is a fundamental component of population change. The number of live births adds to the total population size.
- Deaths Deaths: This is a fundamental component of population change. Mortality reduces the total population size. The difference between births and deaths is termed "Natural Growth."
- Migration Migration: This is the third component of population change. It involves the movement of people into (immigration) or out of (emigration) a region. When combined with natural growth, it determines the "Actual Growth" of the population.
- Density Density: This is NOT a component of change. Population density is a derived metric representing the ratio of people to land area (usually expressed as persons per square kilometer). While changes in population components (births, deaths, migration) will alter the density, density itself is a measure of distribution, not a process that drives population change.
Key Takeaway:
The three components of population change are births, deaths, and migration. Population density is a statistical measure of concentration, not a determinant of growth.