The correct answer is option (1) as A. Pleurobrachia - is a member of phylum Ctenophora. B. Radula − is a rasping feeding organ present in phylum Mollusca. C. Stomochord - Rudimentary structure similar to notochord found in the collar region of members of phylum Hemichordata. D. Air bladder − is found in Osteichthyes which provides them buoyancy.