Epithelium provides a rigid shell to prevent punctures. Epithelium has capillaries to resist iron deficiency. Epithelium insulates the vertebrate from hypothermia. Epithelium prevents dehydration in vertebrates.
I gave my students this multiple choice question: Which explains how the epithelium offers protection to land-dwelling vertebrates?

Only one answer is correct among these 4 choices:
- Epithelium provides a rigid shell to prevent punctures.
- Epithelium has capillaries to resist iron deficiency.
- Epithelium insulates the vertebrate from hypothermia.
- Epithelium prevents dehydration in vertebrates.

Could you tell me which one is correct?

Epithelium prevents dehydration in vertebrates.