endothermic (warm-blooded) slimy skin ectothermic (cold-blooded) hairy skin
I gave my students this multiple choice question: Which characteristic is common to all reptile species?

Only one answer is correct among these 4 choices:
- endothermic (warm-blooded)
- slimy skin
- ectothermic (cold-blooded)
- hairy skin

Could you tell me which one is correct?

ectothermic (cold-blooded)