Answer: The detail from the text that best supports Sophie's topic sentence is C. Snow from a tree branch soaked the man’s newly built fire.
Explanation: A topic sentence expresses the main idea or point of a paragraph; therefore, it summarizes the information that is going to be presented in that paragraph. Moreover, the rest of the sentences in that paragraph must provide evidence that support the topic sentence. In that way, as the topic sentence about Jack London's "To Build a Fire" makes reference to the way in which nature affects prospectors, the detail from the text that best supports it is C. "Snow from a tree branch soaked the man’s newly built fire" since it presents a situation in which a natural element (snow) caused a difficulty to a prospector.