Why are processes of population change useful for development planning?

Correct answer: They show why the population is changing

The correct answer is A: these processes show why the population is changing. Development planning must respond not only to the number of people but also to the reasons behind change. Planners study births, deaths and migration to understand whether a population is growing, declining, ageing or receiving many newcomers. This helps estimate future needs for schools, hospitals, houses, jobs, transport, water and other services. B is wrong because rainfall is a climate factor, not the meaning of population-change processes. C is wrong because the age of mountains is studied through geology and physical geography. D is wrong because map colour is a cartographic choice and has no role in explaining demographic change. The important idea is that reliable planning requires evidence about both the size and the movement of population. Memory cue: population processes answer “how and why is the population changing?”