they have scaly skin. they have slimy skin. their body temperature stays at a constant level. their body temperature changes with the environment.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Reptiles become more active as the day gets warmer. This is because
Possibilities:
- they have scaly skin.
- they have slimy skin.
- their body temperature stays at a constant level.
- their body temperature changes with the environment.

their body temperature changes with the environment.