If an area has low density but people are settled only along the river, which conclusion is correct?

Correct answer: Internal distribution is uneven

An average density describes the whole area, but settlement may be concentrated in only one part of it. If people live mainly along a river, the river corridor may be relatively crowded while distant inland areas remain sparsely settled or empty. The overall average can therefore be low even though a narrow local zone has a high concentration. Physical features and access to water, transport, fertile land, or jobs may influence this pattern.

Option A is correct because the population is not spread evenly across the entire region. Option B contradicts the stated river-side concentration. Option C is wrong: average density can still be calculated, although it does not fully describe the internal pattern. Option D is also wrong because rivers can support settlement by providing water, transport routes, fertile land, or other advantages. The key is to distinguish average density from local distribution.