Excerpt from Ocmulgee National Monument: A Place in History Marie Devers All around the Ocmulgee National Monument, evidence of several different civilizations exist. Researchers can estimate the years when a civilization thrived based on the items that they left behind. By dating these items, scientists have determined many facts about the people who lived in this area. After one civilization faded, another group developed on a different section of the land. In the center of these civilizations, the people built large flat-topped mounds. These structures are one of the most remarkable features of the area. According to the passage a mound is a
A) fence.
B) cemetery.
C) large hill.
D) town square.