Fact 1: Mollusks have a circulatory system with one or two hearts that pump blood.

Fact 2: Clams, oysters and snails are familiar mollusks.

Given the two facts above, answer the question "have a circulatory system with one or two hearts" with the following options: 
- Birds
 - alpacas
 - elms
 - Clams
 - salmon
 - animals
 - toads
 - complex


 

    Clams     