Answer:
C
Since all the water that was needed for irrigation was frozen into icebergs, early humans could not plant.
Answer: Well, from ancient Rome to the collapse of the Mayan empire, there have always been a few key features that contributed to civilizations crumbling: uncontrollable population movements, epidemic diseases, failed states leading to increased warfare, narrowing trade routes. Among possible causes of a collapse of society are natural catastrophes, wars, pestilences, famines, and population declines. The collapse of a society may result in its return to a more primitive state, its incorporation into a stronger society, or its total disappearance. Regardless of civilization size or complexity, virtually all civilizations have been destroyed by this fate.
Explanation:
This is the answer I think is correct but thxs for points
