What is the option General Zaroff gives to the men he captures?

The men Zaroff captures can either play the game or be turned over to Ivan.

"Oh," said the general, "I give him his option, of course. He need not play that game if he doesn't wish to. If he does not wish to hunt, I turn him over to Ivan. Ivan once had the honor of serving as official knouter to the Great White Czar, and he has his own ideas of sport. Invariably, Mr. Rainsford, invariably they choose the hunt."