Choices: A. a hydraulic system; B. streams.; C. The Caspian Sea; D. kalenchoes; E. near the shoreline; F. swamp vegetation; G. Calcium carbonate; H. patch reefs;

Fact 1: Lakes are formed by precipitation and runoff. Fact 2: The Caspian Sea is, strictly speaking, not really a sea but instead the world's largest lake. Given the two facts above, what was formed by precipitation and runoff?
Answer:
C.