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

Fact 2: Ancathostega is one of the earliest tetrapods found, and by far the most complete.

Given the two facts above, answer the question "What do ancathostega have four of?" with the following options: 
- Eggs
 - feet
 - Wings
 - alveoli
 - Lungs
 - ovaries
 - rings
 - Limbs


 

        Limbs 