A student is researching the effects of water pollution on community health. She learns that communities with high
levels of water pollution report higher rates of illness and
have shorter life spans. When the pollution levels drop,
these problems seem to disappear quickly.
The student described in the passage is learning about which theme of
geography?
A. Movement
B. Region
C. Location
D. Human-environment interaction

d. stage 4

explanation:

the existence of some kind of demographic transition is widely accepted in the social sciences because of the well-established historical correlation linking dropping fertility to social and economic development.[1] scholars debate whether industrialization and higher incomes lead to lower population, or whether lower populations lead to industrialization and higher incomes. scholars also debate to what extent various proposed and sometimes inter-related factors such as higher per capita income,lower mortality, old-age security, and rise of demand for human capital are involved.[2]

tension is the type of stress that results when two tectonic plates diverge .

explanation: