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: Earthworms live underground in the soil. As they move through the soil, they create tunnels. The tunnels help improve the soil. Plants grow better in soil that has earthworms. Which statement explains how earthworm tunnels help plants?
Earthworm tunnels loosen the soil so plant roots can easily grow
Improve soil structure for better plant growth.