Which option correctly shows the scale problem in population growth analysis?

Correct answer: National growth may be moderate but a city may grow fast due to migration

Direct answer: Option A is correct. Scale means the level at which we study a population pattern, such as local, regional, national or global. A country may show moderate overall growth, while one city receives many migrants for employment or education and therefore grows rapidly. The national average can hide this local change, so planners must examine more than one scale. Option B is wrong because birth rates, death rates and migration flows differ from place to place. Option C is wrong because local growth affects housing, transport, schools, water supply and jobs directly. Option D is wrong because population growth can be measured at village, city, district, national and world levels. Memory cue: an average at a larger scale can hide a sharp change at a smaller scale.