What is significant about earth's distance from the sun?

The Earth is far enough away from the sun to not be burned like Mercury or Venus, but close enough to not be freezing cold like Mars. Earth's position in the solar system is very important for our survival.

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]