I'd say the answer is C
The best answer to the question: How does the event affect plot development, would be: C: It shows that Buck and Thornton have a true understanding of each other´s needs. ;
The key event illustrates the deep bond and mutual understanding between Buck and Thornton. This connection leads to Buck's motivation and significant actions that advance the plot. Therefore, the answer is C: It shows that Buck and Thornton have a true understanding of each other’s needs.
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