D is the correct answer. Panamanians had to fight against Columbia to gain independence and were aided by the United States in the effort for exchange of land to create the Panama Canal. Canada was able to negotiate self-rule and eventually sovereignty from Great Britain. The clean break allowed for a good relationship to continue since.
Spoils system or patronage system (same thing, different name)
Because of the wide variety of people
The correct cause-and-effect relationship which led to World War II is the aggressiveness of Japan, Italy, Germany and Treaty of Versailles’ that caused resentment for the German. Its effect is that this led to the use of nuclear weapons during the war and later led to the Cold War.
