D is the correct answer, with A following quickly behind as a result of D.
The American colonists had a long and complicated history with the Native populations.
Colonists wanted more land and room to grow, and the Native populations obviously opposed that.
The British government tried to contain their colonists but to no avail.
During the war, many tribes fought against the colonists because they saw the colonists as their aggressors and the British as standing between the colonists and them.