Which of the following set of animals belong to a single taxonomic group?
Arthropoda - Lepisma (silverfish), Locusta (Locust), Rhopalocera (Butterfly), Bombyx (silkworm)
Cnidaria - Pennatula (Sea pen), Gorgonia (Sea fan), Aurelia (Jelly fish)
Annelida - Pheretima (Eartthworm)
Mollusca - Aplysia (Sea hare), Sepia (Cuttlefish)
Aschelminthes - Ascaris (Roundworm)