Which of the following features is common to earthworm, prawn, and lancelet?

Earthworm (Annelida), prawn (Arthropoda) and lancelet (Cephalochordata) exhibit metamerism. Gills are absent in earthworm. The respiratory pigment in the prawn is haemocyanin.  A respiratory pigment is absent in the lancelet. Nephridia are present in the earthworm; protonephridia are present in the lancelet; green glands are present in the prawn.