What option do the huntees get if they don't want to be hunted in the most dangerous game

"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."

Answer:

Zaroff lets Ivan do whatever he wants with them.