Which option gives the correct data needed to measure population change?

Correct answer: Births, deaths, in-migration, out-migration and the time period.

Answer: A. To measure population change, we need data showing how many people were added, how many were lost, and over what period the change occurred. Births add people, deaths remove people, in-migration adds residents from elsewhere, and out-migration removes residents who leave. A is correct because it includes all four major demographic flows and the time period needed for comparison. The figures can be used to understand the change in a population, while the exact calculation may also require a starting population. B is incorrect because physical measurements of rivers, mountains and soil do not measure demographic change. C describes natural resources or biodiversity, not population flows. D describes cultural features and is not sufficient for this measurement. Memory cue: count additions, losses and time—births, deaths, in and out.