Provide your best answer for the following question. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The question is: When water evaporates from Earth's surface into the atmosphere, its molecules enter the gas state. What change in this gas causes molecules to condense into the small water droplets that form clouds?
The temperature is reduced.
Cooling.