It is D, the ottoman empire. It' not A because the byzantine's were part of the ottoman empire. The Mongols were eastern asia so that wouldn't be it. And the roman empire had already fell by the time the Ottoman empire had rose. So you have your answer! Hope I helped. :)
They used them to keep the people who they captured. They captured these people because they either were or looked like Jews. These people were put under harsh conditions going to the concentration camps. They also kept prisoners of war in there. Obviously, nobody wanted to go there. If you want to know more look up Anne-Frank's story. She wrote everything she lived during the time Hitler ruled. She died though and didn't make it out alive. She also went to a concentration camp if I remember correctly.
Hope this helps!
Most likely irony. Paradise is usually instilled in peoples' minds as somewhere refreshing and heavenly, and the next couple of words say "ahead of them is an empty oil-covered beach" which clearly objects with the paradise statement.
The answer is A. Ending the institution of slavery.
