I missed Netherlands. I typed "Holland" (as the other quizzes admit also the use of this "alternative" name), but this quiz doesn't consider it valid.
It probbly does not help contemporary Jewish communities in Poland that the government has now made it illegal to discuss Polish state complicity in Holocaust-era murders of Jews. This makes not only historical research difficult, but may well lessen reckoning and trust building.
Doris Bergen's 'War & Genocide: A Concise History of the Holocaust' is an excellent overview, and gets into Soviet-Polish-Nazi interregna.
And to read about some of the incredible resistance efforts, especially in Eastern Europe, along with a detailed profile of Jan Karski, I highly recommend Nechama Tec's 'Resistance: Jews and Christians Who Defied the Nazi Terror'.