Zaroff respects Rainsford and thinks that he will be a worthy opponent.
Explanation:
According to the interaction between Zaroff and Rainsford, Zaroff is enthusiastic and looks forward to playing Rainsford as he believes he is facing a man of equal strength and abilities. He was wary to wager with Rainsford because he knew he was a worthy opponent.
Therefore, Zaroff respects Rainsford and thinks that he will be a worthy opponent.
