The Circulatory System of Earthworms Is

The circulatory system of earthworms is

A) closed with hearts pumping blood to the anterior arteries and veins returning from the posterior.
B) open with blood "washing" through the coelomic cavity.
C) half closed with hearts pushing blood toward the head but washing posteriorly through an open cavity.
D) closed with dorsal and ventral blood vessels joined by five paired "hearts" forcing circulation flow dorsal-ventrally.
E) absent and they rely solely on diffusion to absorb gases through the epidermis.