The event you are referring to appears to highlight Thornton's reliance on Buck, which contributes to the development of the plot by demonstrating a critical bond between the two characters. Specifically, the idea that "Thornton needs Buck in order to hunt for food" underscores the theme of partnership and mutual dependence, which can propel the narrative forward. This relationship drives their actions and decisions, ultimately influencing the direction of the story.
While each of the options you provided can contribute to character development and thematic depth, the first option stands out as it emphasizes Thornton's need for Buck, setting the stage for their partnership to grow and face challenges together. This reliance could lead to significant plot developments, such as shared adventures, conflicts, or deeper emotional connections that enhance the overall narrative arc.
If you would like to discuss how this specific event connects to broader themes or offers insights into character motivations, please provide additional context!