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 dense, cold air pushes beneath warmer atmospheric air, the lighter, warmer air rises. As this air rises into the atmosphere, it cools and some of the water vapor in it condenses. Which of the following will most likely form as this occurs?
Clouds.