Final answer:
The sentence that encapsulates the theme of 'The Open Boat' is about the bond of comradeship in the face of adversity, emphasizing the profound human connection formed when facing the indifferent forces of nature.
Step-by-step explanation:
The sentence that best captures the theme of Stephen Crane's The Open Boat is: "...there was this comradeship, that the correspondent, for instance, who had been taught to be cynical of men, knew even at the time was the best experience of his life." This theme reflects the profound human connection and solidarity formed in the face of adversity. The story, based on Crane's own experience, conveys the Naturalist idea that human beings are at the mercy of nature, and it is their camaraderie and collective struggle against the indifferent forces of the sea that shapes their reality and internal revelations.