Answer:
C. analyzing the significance of a historical event
Step-by-step explanation:
In the passage, the author presents Blue Clark's study on how conflictive the relation between Native American tribes and the United States Supreme Court was, as Blue Clark indicated the Congress' supreme power left almost no place for negotiation with Native Americans. But the main purpose of introducing this information is to highlight the significance of the historical event that took place and that Blue Clark forgot to consider in his study.