You are presented with the quiz "What do ancathostega have four of?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "amphibians are the first true tetrapods, or vertebrates with four limbs" and "ancathostega is one of the earliest tetrapods found, and by far the most complete". 

So, what's the best answer to the question?


 

        Limbs   