The correct choices for why Native American tribes joined together against the British in Pontiac's Uprising (1763-1766) are:
Choice B: They objected to the British taking over territory that had been ceded by the French, claiming that the French had no right to give away Native American lands.
Choice C: They wanted revenge on the British Empire for its treatment of their allies, the French.
Choice A is not accurate in the context of the reasons Native American tribes joined together in this rebellion. While the British did change trade policies and relations, the primary motivators for the uprising were related to territorial disputes and a response to British policies following the Seven Years' War.