Which of the phylum contains exclusively marine, radially symmetrical, diploblastic organisms with the tissue level organisation?

Step-by-step solution

Members of phylum Ctenophora commonly known as sea walnuts or comb jellies are exclusively marine, radially symmetrical, diploblastic organisms with tissue-level organization. Members of this phylum are found in the depth of the ocean and the property of bioluminescence is well marked in Ctenophora.