You are presented with the question "What sort of circulatory system do frogs, toads, and salamanders share?" and the following answer choices: 
- live birth
 - It helps them survive
 - matter vibrating
 - two-chambered heart
 - Veins and arteries.
 - biological diversity
 - three-chambered heart
 - four-chambered heart

Now knowing that amphibians have a relatively complex circulatory system with a three-chambered heart and frogs, toads and salamanders are amphibians, choose the best answer.


 

       three-chambered heart  