If a region has low average density but some industrial belts are very crowded, what limitation of average density appears?

Correct answer: Average can hide local concentration

The direct answer is A: an average can hide local concentration. Average density is found by dividing total population by total area, but one number cannot show how people are distributed inside every part of a region. Step by step, a large region may contain forests, mountains or empty land; a few industrial belts may contain many people; the total population is then divided by the whole area; the result may be low even though those belts are extremely crowded. Option A is correct because it identifies the limitation of an average. Option B is wrong because an average does not always describe every locality exactly. Option C is wrong because industrial areas often attract workers and settlements. Option D is wrong because density remains useful, although it must be read with local details. Exam cue: use average density for broad comparison, but inspect local variation for a complete picture.