What is the main idea of this text? a The Indians of the Pacific Northwest built permanent villages that housed hundreds of people apiece.

b The Plateau culture area sat in the Columbia and Fraser river basins at the intersection of the Subarctic, the Plains, the Great Basin, the California, and the Northwest Coast culture areas.

c The people living in North America before Europeans arrived can be grouped into ten separate culture areas, each with its own characteristics.

d Many people living in the Great Basin culture area lost their land after gold and silver were discovered there in the mid-19th century.