6. what is the largest mass extinction recorded on earth?

The largest mass extinction ever recorded on earth was that which occurred at the end of the end of the Permian period.

Explanation:

The largest mass extinction of species ever recorded on Earth, which occurred 252 million years ago and eliminated 96% of marine fauna, occurred at the end of the Permian period and was the result of global warming and left the animals of the oceans without sufficient oxygen to survive.

The lack of oxygen caused by global warming explains more than half of the loss of marine diversity in this late Permian mass extinction and other factors, such as acidification or changes in the productivity of photosynthetic organisms, acted as additional causes, according to these scientists.

The situation at the end of the Permian, when the increase of greenhouse gases in the atmosphere generated higher temperatures on Earth, is similar to the current one.

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]