Answer: The Water
Explanation:
The boiling litre of water has more volume and so has more heated molecules per cubic metre so it will have a higher amount of heat than the glowing nail.
To practically test this, put the glowing nail into a litre of cold water and record the final temperature when the nail has cooled down. Repeat this with the boiling litre of water. You will notice a higher final temperature with the boiling water indicating that it had more heat.
