Question

what environmental change allowed people to travel by land between asia and north america?
○ human adaptation to arctic environments
● ice sheets blocking sea routes
○ the formation of ice sheets on land
○ the melting of ice sheets on land

Explanation:

During the last Ice Age, lower sea - levels due to large amounts of water being locked up in ice sheets created a land bridge (Beringia) between Asia and North America. Ice sheets blocking sea routes is not the correct reason. Human adaptation to Arctic environments is about human ability to live there, not the environmental change for land travel. The formation of ice sheets on land is not what allowed land travel. The melting of ice sheets on land is also incorrect as it was the lowering of sea - levels due to ice accumulation elsewhere that mattered. The key environmental change was the exposure of the land bridge due to lower sea - levels related to ice sheet formation in other areas.

Answer:

None of the above options are correct. The correct environmental change was the lowering of sea - levels due to glaciation during the Ice Age, which exposed a land bridge (Beringia) between Asia and North America.