cold milk warm soup water melting from ice steam rising from boiling water
I gave my students this multiple choice question: Students study how the temperature of a substance is related to the rate of molecular movement. The molecules in which substance are moving the fastest?

Only one answer is correct among these 4 choices:
- cold milk
- warm soup
- water melting from ice
- steam rising from boiling water

Could you tell me which one is correct?

steam rising from boiling water