Final answer:
The name of Chaya's original Resistance group in the book is the Jewish Combat Organization, known as the ZOB.
Step-by-step explanation:
In the book Resistance, Chaya's original Resistance group is not named directly, but we can deduce that it was not the Akiva, the Judenrat, or none of the above, but rather the Jewish Combat Organization, which is known as the ZOB (b). The ZOB was a well-known resistance organization during World War II, specifically within the context of the Jewish Resistance efforts in ghettos like Warsaw. This group is noted for their heroic stand against the Nazis during the Warsaw Ghetto Uprising when facing deportation to concentration camps in 1943, a significant historical event that has been depicted or referenced in various works that portray Jewish resistance during the Holocaust.