A bird builds its nest in a cactus. A rattlesnake shakes its tail when threatened. A lizard crawls under a rock for shelter. The ears of a jackrabbit release heat.
Which statement best describes a structural adaptation that helps an organism survive in a desert?

Options:
- A bird builds its nest in a cactus.
- A rattlesnake shakes its tail when threatened.
- A lizard crawls under a rock for shelter.
- The ears of a jackrabbit release heat.

The ears of a jackrabbit release heat.