Answer:
Correct answer is They were sent to 1 of 10 concentration camps throughout the western United States.
Step-by-step explanation:
The last option is correct as there were 10 camps located mostly in the western part of the country, mostly in California, Arizona, Colorado, Utah.
First option is not correct as until 1943 no man of Japanese descendant was able to join the army.
Second option is not correct as they were not sent back to Japan, but to this camps.