If a hilly state has low average density but valleys have high density, what does this prove?

Correct answer: Local physical conditions change population density

Correct answer: A — local physical conditions change population density. A state-wide average is calculated by dividing the total population by the total area. It gives a broad picture, but it does not mean that people are spread equally everywhere. Hilly regions may contain steep slopes, high mountains and difficult transport routes, where settlement and construction are harder. Valleys are often relatively level and may provide better access to water, roads, farms, markets and services. Therefore, people can be concentrated in valleys even when the state’s overall average density is low. Option B is wrong because the example itself shows uneven distribution. Option C is wrong because valleys can be suitable places for settlement. Option D is wrong because an average can hide important local differences. Memory cue: state average is a summary; relief explains where people actually cluster.