This question is about "The Call of the Wild"
Answer:
Buck's kidnapping had the biggest impact
Step-by-step explanation:
Buck lived with his owner who was very good for him, met all its needs, making it a pampered dog, well fed and loved, in other words, Buck had a very comfortable life, with everything it could need, but its life took a drastic turn when he was kidnapped to be a treetop dog. There, Buck suffered abuse and deprivation, but it learned to fight and defend himself, which influenced the rest of its life.