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: Noah visited a park that had many oak trees. Which best describes the role of an oak tree in its ecosystem?
Oak trees are a source of food and shelter for animals.
Provides food and shelter for various wildlife species.