Answer
Snakes are tetrapods, even though they lack limbs, since they evolved from tetrapod ancestors as seen in the relic limb bones in some snakes. They belong to the tetrapod clade.
Work Step by Step
This question is asking you to understand the nature of a clade and how its some of its members may have lost a key, defining feature of the clade. Review earlier material on phylogenetics and clades.
