In what ways did native peoples transform north american environment before european colonization?

Native peoples transform north American environment before European colonization by:•Houses - Whether a house was constructed as a permanent building or with nomadic tendencies in thoughts, resources were put to use in their building. The eldest identified permanent in North America is at Sky City, New Mexico. It stood constructed by the Acoma community which is now riven into Acoma/Laguna. 
•Agriculture - Growing and collecting plants needs fertile soil to be cultured. This need a definite amount of clearance of land. 
•Trails - Nomadic communities would have shaped trails they toured at definite times of the year. Enduring homes would need travel ways whether for water, food or trade. These paths could not relate to the roads we know today but there could be well toured zones in abundance. 
•Tools- Native Americans used numerous kinds of tools. These tools might not have essential a foundry to melt metals but none the fewer there are thousands of tool artifacts that have been found all over North America. Natives formed the landscape everywhere

Your answer is going to be d.

Ithink is b. or c.