It is important because if their names were on the ration books, they would have been found out by the Nazis and taken away, like all of the other Jews.
I hope this answer helped you! If you have any further questions or concerns, feel free to ask! :)
As long as you clearly state the sources and resources of information it should be fine.
Answer:
Happy New Year My Dear Friend
Hhhhhh hhhhh hhhh hhhh h hh h h h h h h