D- They provided guns and supplies to the American Indians in the Northwest Territory.
Explanation:
Direct quote from lesson text:
"Even though the Revolutionary War was over, the British sometimes clashed with Americans in the Northwest Territory. <u>The British sold guns and other supplies to American Indians.</u> The American Indians used the tools to raid American settlers. Violence in the area led to the Northwest Indian War, a series of battles starting in 1785. British soldiers did not fight in most of these battles."
