Why can total population decrease even when birth rate is high in an area?

Correct answer: If deaths and out-migration are very high

Direct answer: A is correct. Population change depends on several components, not on the birth rate alone. A useful relationship is: change in population = births + in-migration − deaths − out-migration. A high birth rate adds people, but the total can still decrease when deaths and the number of people leaving are greater than births and people entering. For example, an area may have many births but lose even more residents because of poor conditions, disasters, lack of jobs, or other reasons. B is generally incorrect because high in-migration adds residents and makes a fall less likely. C is incorrect because fewer deaths remove fewer people and normally support population growth. D is incorrect because better services do not automatically cause a decrease; they may reduce deaths or attract residents. The result must be judged by the combined balance of all four components. Memory cue: add births and arrivals, subtract deaths and departures.