Fact 1: Mollusks have a circulatory system with one or two hearts that pump blood. Fact 2: Clams are mollusks that live in the sea or in freshwater. Given the two facts above, answer the question "what have a circulatory system with one or two hearts that pump blood" with the following options: - a fish - aorta - bacteria - animals - clams - plants - sharks - Birds
A:
clams