If I have Sigarda, Host of Herons in play, whose rule text says.
Spells and abilities your opponents control can't cause you to sacrifice permanents.
And my opponent plays Remorseless Punishment:
Target opponent loses 5 life unless that player discards two cards or sacrifices a creature or planeswalker. Repeat this process once.
Can I choose to sacrifice my creatures, avoiding this effect due to Sigarda, or am I forced to choose another option?