In which situation will migration change population distribution but not directly change national total population?

Correct answer: Internal migration within the country

Direct answer: B is correct. Internal migration means that people move from one part of the same country to another. The source region loses people and the destination region gains them, so the distribution of population changes. However, the people remain within the country, so the national total does not directly increase or decrease because of that movement. Option A involves people entering from another country, so it can increase the national total as well as alter distribution. Option C increases natural population change through more births. Option D can also increase total population by reducing deaths, but it is not migration. The key distinction is between redistribution inside a country and movement across national borders. Memory cue: internal migration relocates people; international migration changes the country total as well.