The three conflicts in America that you are referring to likely include major events or periods such as the Civil War, the Civil Rights Movement, and possibly more recent conflicts related to social issues or political strife. Based on the answer choices provided, the option that best encapsulates a common theme among many significant conflicts in American history, particularly those involving systemic issues, is:
C. they were all the result of racist agendas and policies.
While option D, "they were all driven by fear during a time of crisis," might also apply to specific conflicts, the underlying influences of racial agendas and policies are a persistent and central factor in many American conflicts, including those suggested.