Fact 1: Amphibians are the first true tetrapods, or vertebrates with four limbs.

Fact 2: All frogs are amphibians.

Given the two facts above, answer the question "What are vertebrates with four limbs?" with the following options: 
- humans
 - frogs
 - fish
 - Birds
 - phytoplankton
 - coral
 - bears
 - goats


 

  frogs       