I'm not really sure if you need a broad or detailed definition of the policy, but I'm assuming you want a broad explanation.
The US Policy of Containment was a policy put forth during the Cold War to limit the influence of communism around the globe by attempting to prevent the spread of communism from Russia to other countries around the world. Hope that helps :)
Chinese Immigrants and Mexican Americans
When the african americans moved to the north that was called immigration
I am pretty sure your answer is B
