Final answer:
Zaroff considers Rainsford a worthy opponent, creating a tense dynamic that propels the plot forward and builds suspense.
Step-by-step explanation:
The interaction between the hunters reveals that Zaroff thinks of Rainsford as a worthy opponent. This viewpoint serves to advance the plot by establishing a dynamic tension and competition between the two characters, setting up the cat and mouse game that comprises the crux of the narrative. Zaroff's perception of Rainsford adds depth to their relationship and builds suspense for the reader.