I'd have to say D is the correct one.
The correct you are looking for is the anwser "A"
Answer: It is a part of the rising action that shows a conflict between the dogs.
Explanation: Usually in a pack of dogs, there will be a fight for dominance. Spitz intruded Buck’s nest to show him that he was top dog, which would have been seen as a challenge to Buck, and it shows a battle will follow soon.
Answer:
I believe your answer is "reflect on the problems and challenges in the world"
Explanation: