In which situation can migration affect the economy of the source region?

Correct answer: When working people leave in large numbers

Answer: C. The source region is the place from which migrants leave. If many working-age people move away, the local labour force may become smaller. This can reduce the availability of workers for farms, factories, shops or services, especially when the departing workers had important skills. Local production and household income may change as well. At the same time, migrants may send remittances home, so the economic effect is not always entirely negative; it depends on the kind of migration and the circumstances. Option A concerns rainfall, not migration. Option B merely says that area stays the same and gives no population movement. Option D, a census, counts or records population but is not itself migration. Memory cue: for a source region, ask “Who is leaving, and what work or income do they take or send?”