The correct answer is - c. Germans.
During the World Wars the Germans in the United States where the object of prejudice, seen as suspicious, and discriminated against. That was a result of the United States and Germany being on different sides during the two wars and fighting against each other.
The Germans living in the United States, immigrants from before the wars, even though had nothing to do with the actions of their country of origin, were seen by many people as they actually are accomplices. In order to avoid segregation in the society and being marginalized, the Germans started changing their names and surnames on a large scale, stopped speaking the German language, as well as letting go of their culture, which led to total Americanization of the ethnic Germans in the United States.