Birds lay eggs and reptiles do not. Reptiles are meat-eaters and birds are not. Birds breathe oxygen and reptiles do not. Reptiles are cold-blooded and birds are not.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: What is one difference between birds and reptiles?
Possibilities:
- Birds lay eggs and reptiles do not.
- Reptiles are meat-eaters and birds are not.
- Birds breathe oxygen and reptiles do not.
- Reptiles are cold-blooded and birds are not.

Reptiles are cold-blooded and birds are not.