Which Invertebrate Animal Group is Characterized by Having a Closed

Question

Which invertebrate animal group is characterized by having a closed circulatory system?
A) Arthropoda
B) Echinodermata
C) Nematoda
D) Annelida
E) Platyhelminthes

Accepted Answer

Annelida is the invertebrate group characterized by having a closed circulatory system, where blood is contained within vessels.