HELP ASAP! WILL MARK YOU BRAINLIEST AND GIVE YOU 20 POINTS!

Answer: It would be the boiling point.
Explanation:
Because it is not a liquid nor a gas, that would mark the last two out. I'll have to guess that it is the boiling point of water.
It would be the second one. This is because if the ice is starting to melt and A is 0 it is getting hotter and 100 degrees is the melting point of water.