Need Help With Aristotlee?

I'm in a Philosophy class and this is a practice final exam question. we need to say what Aristotle believes is the virtuous thing to do in both situations? Which virtues would be displayed? Can anyone please help because i've read Aristotle Nicomachean Ethics like 3 times and I still don't get it...anyways here is the case...Case #1:
The Young Lady:

It is 1942 and you are a young Jewish woman, deeply committed to your faith, living just outside of Paris. The Germans have occupied France for some time now, have set up a government of their own and are enforcing many of their own laws. As the government has been engaged in the practice of deporting all Jewish citizens to concentration camps and systematically killing them, you are working with an “underground” system that has successfully enabled hundreds of Jewish citizens living in Paris to escape the country and avoid the German authorities. Your role in this “underground” railroad is minor, but given the nature of the cause your work is obviously very important to you.

While you have managed to keep your Jewish identity hidden from German authorities, there arises a certain situation. One day, while working for a small bookshop in Paris, the owner, who does not know that you are Jewish, begins talking about how much he dislikes Jewish people, that he believes they are the cause of many if not all of the problems that plague Europe today, and that he has been working with the government as an informant. “Because of me,” he boasts, “many Jews who have hidden their identity from the government have been discovered and ‘dealt with.’” 

He continues to insult Jewish people and their faith. You feel like you must say something because of the constant insults, but you fear that by revealing your faith you most likely will be sent to your death. What is the virtuous thing to do?