The correct answer is B.
After the attack on Pearl Harbor on December 7th 1941, President Franklin D. Roosevelt issued Executive Order 9066. This order stated that any or all citizens who live in specific "military areas" may be moved as deemed "necessary" or "desirable." In this case, Japanese-American citizens were seen as ones that the American military desired to move. This is because the American government feared that Japanese-American citizens would reach out to the Japanese military/government to inform them of America's next move. This sense of paranoia caused hundreds of thousands of Japanese-American citizens to live in internment camps during World War II.