Final answer:
The correct answer is fortitude.
Step-by-step explanation:
The correct answer to fill in the blank in the given context is fortitude.
Fortitude refers to courage in the face of adversity or difficulty. In the context of the sentence, the individuals displayed fortitude to survive the harsh conditions and challenges they faced in Auschwitz.
For example, they may have shown fortitude by finding ways to endure physical and emotional hardships, helping and supporting each other, and making calculated decisions to increase their chances of survival.