You are presented with the quiz "What was formed by precipitation and runoff?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "lakes are formed by precipitation and runoff" and "the Caspian Sea is, strictly speaking, not really a sea but instead the world's largest lake". 

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


 

   The Caspian Sea        