The correct answer is - C. British.
The Chickasaw and the Cherokee tribes were having disputes and on going battles with other tribes for territory. Some of the tribes that they were engaged in battles with were the Shawnee and the Choctaw. The Shawnee and the Choctaw were tribes that were allied with the French, and that put the Chickasaw and the Cherokee in not the best of situations. As a response to that, they allied with the British, as much as an unnatural alliance it may have been. Both, the British from one side and the Chickasaw and Cherokee on the other side, had the same interest about the disputed territory, so they allied and managed to overcome the French supported tribes.