The Clovis Tradition, a Sophisticated Stone Technology Based on a Sharp

The Clovis tradition, a sophisticated stone technology based on a sharp point that was fastened to the end of a hunting spear, flourished (widely but briefly) in the central plains and in what is now the eastern United States. Until recently, the Clovis people were considered the first settlers of the Americas. Recent research now suggests, however, that

A) the members of the Clovis tradition depended on the domestication of horses to make travel possible.
B) most likely the Americas were settled by several colonists who came at different times and perhaps by different routes.
C) the wheel, which has never been found in Clovis sites, was a critical part of an even earlier arrival to the Americas.
D) the Americas were settled by one haplogroup-a lineage marked by one or more specific genetic mutations.
E) various groups of colonists entered the Americas, but they all used the same route.