Why does internal migration not always change the total population of a country?

Correct answer: Because people move within the country’s national boundary

The direct answer is A. Internal migration means movement from one place to another within the same country. A person leaving one district, village or city reduces the population of the place of origin, but that same person is added to the population of the destination. When the whole country is counted, the person is still inside the national population. Thus internal migration usually changes the distribution of people between regions rather than the country’s total number. Option A correctly identifies the national boundary as the key idea. Option B is wrong because going abroad is international migration, not internal migration. Option C is unrelated; moving within a country does not end the birth rate. Option D is also unrelated and is not a necessary result of internal migration. Memory cue: internal movement changes “where people are,” while international movement can change “how many people are in the country.”