I would have to say C. Though take that answer with a grain of salt.
Answer:
C. He ordered Japanese-Americans into camps.
Cultural diffusion is when groups are divided over time due to differences of opinions over time. One example for today would be the presidential election which divides many cultural groups because of the issues which each individual in the group supports.
30 to 60° north, 60 to 120° west
hope this helps :)