Which characteristics best describe earthworms?

A) polychaete; fluid filled coelom
B) oligochaete; open circulatory system
C) moves by longitudinal muscle contraction; hydrostatic skeleton
D) oligochaete; scavengers; closed circulatory system
E) hermaphrodites that fertilize themselves; open circulatory system

Earthworms are classified as oligochaetes, meaning they have few setae or bristles on their bodies. They are also scavengers, feeding on decaying organic matter. Earthworms have a closed circulatory system, which means that their blood is contained within vessels and does not directly come into contact with their tissues. They rely on longitudinal muscle contraction to move and have a hydrostatic skeleton, which means that their body is supported by the pressure of fluid within their coelom. Earthworms are hermaphroditic, but they do not fertilize themselves; they exchange sperm with another individual during mating.