Concentration camps built by Nazis in 1933 initially held Jehovah's Witnesses. gypsies. socialists. political prisoners.

The correct answer is political prisoners

Anyone who was against the regime and the party was imprisoned and put into concentration camps where they had to work. When the war began, other groups of people also were thrown into the camps such as Jewish people, Roma people, Slavs, socialists, and various other groups who were disliked by the Nazi party.

In the initial stages, Concentration camp inmates were political prisoners. In some cases the political prisoners imprisoned early in 1933 remained there until the end of the war.