Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
Oceans are the major source of water vapor in the atmosphere. Sunlight heats water near the sea surface ( Figure below ). As the water warms, some of it evaporates. The water vapor rises into the air, where it may form clouds and precipitation. Precipitation provides the freshwater needed by plants and other living things.


Question: What is the major source of water vapor in the atmosphere?
ocean
Oceans.