Normally, no, there is nothing to respond to. You resolve all parts of Flash's effect before you can put anything else on the stack. But if you want to pay the cost you can use the creature's mana abilities to pay for it, assuming it has haste or does not need to tap, mana abilities do not use the stack and can be used during the resolution of an effect.
While damage is still on the stack, the player who controls that creature has the opportunity to respond to the 'ping' by using the sacrifice outlet or any other instant or ability, if they choose to.
dont know dont caree
The ability to respond to a stimulus is called irritability or responsiveness. It refers to an organism's ability to detect and react to changes in its environment.
Adaptation/Evolution
To React
Imunocompetent
excitability
the ability to respond in a nick of time
irritability
In the book, the creature saw that fire was warm, and so he thrust his hand into the flames, which of course burned him. Ultimately, the creature was confused by it because he understood how to preserve it but not how to make it.
They are Creature Permanents while on the battlefield, Creature Spells while being cast on the stack, and Creature Cards at any other time. So when a player pays the mana cost on a creature card, putting it on the stack, it is now a spell and can be countered by anything that counters spells. After the spell resolves, it is just simply a Creature Permanent.
Discrimination