What did europeans bring to the new world that caused the detahs of millions of native americans?

The colonists brought several things with them that helped destroy the Native American culture. The first thing most people think of concerning this is disease. Disease was a huge factor in the deaths of many Native Americans, but other things came with the colonist that brought longer more subtle changes to the lives of the Native Americans and helped destroy their way of life. Before the fist colony of Jamestown the Powhatan Indians carefully managed the lands they inhabited, and tabcoo.

Ithink the answer should be a.