Final answer:
The dialogue in lines 197-201 contributes to the plot and tension, shifting the narrator's confidence and establishing authenticity for readers.
Step-by-step explanation:
The dialogue in lines 197-201 contributes to the narrative by advancing the plot and increasing tension. It signals a shift in the narrator's confidence to anxiety, as the captain's questioning has a significant impact on him. The dialogue also establishes authenticity and allows readers to directly witness the scene and characters.