The mounds built by the Adena culture were used for all of the following purposes, exceptA. as burial sites. B. for defense. C. as effigies. D. for trapping animals.

Answer: Option (D). For trapping animals.

Explanation: The Adena culture was a pre-Columbian Native American culture that existed from 1000 to 200 BC, The Adena culture refers to what were probably a number of related Native American societies sharing a burial complex and ceremonial system These mounds built by the Adena people generally ranged in size from 20 feet (6.1 m) to 300 feet (91 m) in diameter and served as burial structures, ceremonial sites, historical markers, and possibly gathering places. These mounds were built using hundreds of thousands of baskets full of specially selected and graded earth, more so, the traces of Adena culture are still seen in the remains of their substantial and unique earthworks.

Adena earthworks were often built as part of their burial rituals, in which the earth of the earthwork was piled immediately atop a burned mortuary building, The intention of constructing the mortuary building was to keep and maintain the dead until their final burial was performed.