What does the idiom "pull the chestnuts out of the fire" mean?

To take unnecessary risks

To help someone in a difficult situation

To sacrifice oneself for someone else's benefit

To manipulate others for personal gain

The most appropriate meaning idiom 'pulled the chestnut out of the fire' is 'accomplishing a difficult job for someone else'.

• Pull the chestnuts out of the fire: succeed in a hazardous undertaking for someone else's benefit.