The correct answer is D) 450,000.
During WWII, approximately 450,000 POWs were shipped to internment camps.
POW stands for prisoner of war. These individuals are soldiers or members of the opposite country that are held captive during the war or even after the war has ended. Countries hold prisoners to weaken the opposite army or for negotiations purposes after the war, exploiting them in labor, as a show of victory or supremacy, or punish them for war crimes.
Under the Third Geneva Convention, POWs gained some rights such as allowing to communicate with family members, be treated with respect, be given enough food and water, being paid for the work done, and being released as soon as the war ends.
The other options of the question were a) 900, b) 50,000, and c) 120,000.