It also helped that he didn't know the Nazis were trying to slaughter all Jews, something he says he and other prisoners learned only after liberation.

The correct answer to this open question is the following.

You forgot to include the question. Here you just attached a statement, but you are no asking a question.

However, doing some research, we can help you with the following general comments.

That quote belongs to Jack Mandelbaum, regarding the Holocaust.

Journalist Soraya Sarhaddi Nelson wrote the article titled "A Holocaust  Survivor, Spared From Gas Chamber By Twist of Faith,"in January 2015.

She wrote this story about Jack Mandelbaum as part of the commemoration of the 100 years from the Jewish liberation from Auschwitz, a concentration camp during World War II, where the Nazis killed Jewish people in the gas chambers.

d. japan's attack on pearl harbor