Which of the Following Group of Organisms Have a Closed

Question

Which of the following group of organisms have a closed circulatory system?
A)Hydra
B)Grasshoppers
C)Earthworms
D)Crayfish
E)Clams

Accepted Answer

The circulatory system of an earthworm consists of a series of hearts that pump blood into a ventral blood vessel.See figure 30.1B.