You are presented with the question "What was formed by precipitation and runoff?" and the following answer choices: 
- a hydraulic system
 - streams.
 - The Caspian Sea
 - kalenchoes
 - near the shoreline
 - swamp vegetation
 - Calcium carbonate
 - patch reefs

Now knowing 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, choose the best answer.


 

   The Caspian Sea      