Final answer:
The issue that deeply troubled Native Americans regarding European colonization efforts in the 17th century was the introduction of new diseases, loss of cultural identity, and forced displacement.
Step-by-step explanation:
The issue that deeply troubled Native Americans regarding European colonization efforts in the 17th century was d) All of the above.
The introduction of new diseases, the loss of cultural identity, and forced displacement were all significant problems faced by Native Americans during this time.
European colonization brought diseases like smallpox, which Native Americans had no immunity to, resulting in high mortality rates. Additionally, the colonizers imposed their religions, ideas about property and goods, often displacing and forcing Native Americans off their lands.