The fact that yoga and acupuncture have been adopted into american culture and are increasing in popularity is an example of

answer; i believe the correct answer is (religious issues);

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]

b.

developed countries have tended to improve the environment, while developing countries have tended to damage it.