Hello. You have not indicated which text the question refers to. This makes it impossible for the question to be answered efficiently and satisfactorily.
However, a section called "The Holocaust" should provide context for a line that refers to the cruelty that the Nazis inflicted on Jews, Poles, Sigans, prisoners of war and other people who were persecuted and subjugated by Nazis, especially Jews who were almost exterminated during the holocaust.
In this case, to find the answer to your question, you need to read the opening text and find the section that points to these elements.
