In which situation can high density create both economic benefit and challenge?

Correct answer: When people provide market and labour but also increase pressure on services

Direct answer: Option A is correct. High density can bring benefits and difficulties at the same time. A large population in one area can provide workers, customers, skills, businesses, and a large market. However, if housing, water, transport, schools, hospitals, sanitation, and jobs do not grow fast enough, pressure on services and the environment increases. Step by step: more people create a larger labour force; businesses gain customers and may expand; economic activity can rise; then demand for services also rises; limited facilities may become overcrowded, producing challenges. Option A gives both sides and is therefore the balanced answer. Option B is wrong because a vanished population cannot supply labour or create service pressure. Option C is wrong because a dense population usually creates service demand. Option D is wrong because economic activity can be stimulated by markets and labour, so its absence is not the stated benefit-and-challenge situation. Memory cue: density means more opportunity, but also more pressure if planning is weak.