You are presented with the quiz "To identify that liquid 's boiling point requries" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "heating a liquid can be used to identify that liquid 's boiling point" and "heat is caused by vibrations of the atoms and molecules of substances". 

So, what's the best answer to the question?


 

 vibrations of the atoms          