Which of the following organisms has an open circulatory system?

a) Dogs b) Spiders c) Earthworms d) Squid

B. Spiders

Explanation:

The open circulatory system is a type of circulatory system in which the blood bathes the tissues directly. It is a characteristic of arthropods and many mollusks. Spider is an arthropod and have an open circulatory system. Spiders have a dorsal, tubular heart that serves to pump hemolymph into a dorsal artery. The arteries deliver the hemolymph into the hemocoel, the large spaces that collectively make a blood cavity. The heart has openings in its walls. These openings are called Ostia through which hemolymph re-enters the heart.