The correct answer is A) It was believed they were working against the war effort.
Immigrants from Germany and Austria-Hungary were treated poorly during the war because it was believed they were working against the war effort.
During World War 1, there were many people from Germany and the Austria-Hungary Empire living in the United States. It was a tough time for them because they were in America but their families were in Europe fighting in the war or suffering the consequences of the war. These immigrants in America were not well accepted in those years and were victims of discrimination, rejection, and mistrust because American citizens thought that they could be supporting their native countries and not helping the United States.