The number of people living in a unit area of land is termed its

Step 1: Analyze the question The question asks for the term describing the number of people living in a unit area of land (for example, per square kilometre).

Step 2: Explain the concept Population density measures how crowded an area is. The formula is:

Population density = Total population ÷ Total land area

For example, if a town has 500,000 people living on 250 km², its population density is 500,000 ÷ 250 = 2,000 persons per km².

Step 3: Check each option

• A. Birth rate: the number of live births per 1,000 people in a year. It measures births, not how people are spread over land.
• B. Death rate: the number of deaths per 1,000 people in a year. It is not related to land area.
• C. Dependency ratio: the ratio of dependents (children under 15 and elderly people over 64) to the working-age population (15-64). It has nothing to do with land area.
• D. Population density: the number of people per unit area of land. This matches the question exactly.

Step 4: Answer The correct answer is D. Population density.

Exam tip: Look for the keyword "unit area" or "per square kilometre". Whenever you see it, think density. Birth and death rates always involve "per 1,000 people", and dependency ratio always involves "age groups".