Answer:
The sentences that would best serve as evidence of the theme "sometimes survival depends on knowing when not to fight" are:
He saw, once for all, that he stood no chance against a man with a club. He had learned the lesson, and in all his after life he never forgot it.
Step-by-step explanation:
The dog Buck is the main character in Jack London's novel "The Call of the Wild". The story revolves around the idea of survival of the fittest, meaning that only those who are strong and adaptable can survive and thrive in this world. Buck is a true survivor; an efficient one. He goes from living a comfortable life in a country home to, in the end, leading a pack of wolves. He is stolen from the ranch where he lived and sold to be a sleigh dog. It is Buck's physical strength and his incredible capacity to learn and adapt to new circumstances that allow him to survive and become a leader and companion. The sentences that show his learning skills and adaptability are:
He saw, once for all, that he stood no chance against a man with a club. He had learned the lesson, and in all his after life he never forgot it.
If Buck hadn't understood that it was better not to fight, he would have been beaten again by the "man with a club". He might even have ended up dead, since the man could very well have decided it was no use keeping an untamable dog.