This question is probably connected to a story in whatever class your in but speaking for my immigrant parents.
They were probably scared crossing and getting caught being here. Keep in mind that many immigrants come here because this country is full of opportunities for a better for people’s future generations. Wherever they came from was keeping them away from that.
Yes, the answer is D) to control all German-speaking nations. Hope this helps anyone out there. :)
Try searching it up in google first
the league of Nations was an alliance with the mission to stop wars in deal with stuff diplomatically. the United States Senate wanted to go back to being isolationist.