Answer the following question given this paragraph: 

Population density is the average number of individuals in a population per unit of area or volume. For example, a population of 100 insects that live in an area of 100 square meters has a density of 1 insect per square meter. If the same population lives in an area of only 1 square meter, what is its density? Which population is more crowded? How might crowding affect the health of a population?.


Q: What is the term for the average number of individuals in a population per unit of area or volume?

 Choices:

- population diameter

- population structure

- Density group

- population density

A:
population density
