Explain in short about population composition importance in planning

Population composition refers to the demographic makeup of persons within a geographic area. The composition of an area's population is useful in projecting the incidence of disease and death, and thus health care needs and demand. ... Knowledge regarding changing demographic composition over time is also important. Population data is essential for planning purposes. Any country needs to know the size and composition of its population – around age and sex structure, among other factors. ... That helps to plan how many schools, clinics, hospitals and jobs a country needs.

yes

Explanation:

there are many population in high land

answer; researchers typically cannot control people's sexual behaviors as would be necessary in an experiment;

the answer is either c or d i think its d