While resolving the triggered ability of Torment of Scarabs, the enchanted player chooses a card to be discarded without revealing it, chooses a nonland permanent to be sacrificed, or chooses to do neither. Then that player discards that card, sacrifices that permanent, or loses 3 life. That player can always choose to lose 3 life, even if he or she has cards to discard or nonland permanents to sacrifice.