Question: what group of animals do octopus belong to
[{'answer': 'class Cephalopoda', 'provenance': [{'wikipedia_id': '22780', 'title': 'Octopus', 'start_paragraph_id': 1, 'start_character': 145, 'end_paragraph_id': 1, 'end_character': 162, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '22780', 'title': 'Octopus', 'start_paragraph_id': 1, 'start_character': 43, 'end_paragraph_id': 1, 'end_character': 946, 'bleu_score': 0.7039433468860331, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14192136795087476301}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '31528468', 'title': 'Cephalopod attack', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['nding and hunting. They are often confused with armsoctopuses have eight arms, while squid and cuttlefish have eight arms and two tentacles. These tentacle', 'Cephalopods are members of the class Cephalopoda, which include all squid, octopuses, cuttlefish, and nautiluses.', 'arious accounts of cephalopod attacks on humans have been reported since the 13th century. Cephalopods are members of the class Cephalopoda']}}]}, {'provenance': [{'wikipedia_id': '22780', 'title': 'Octopus', 'section': 'Section::::Abstract.', 'start_paragraph_id': 1, 'end_paragraph_id': 1, 'meta': {'evidence_span': ['The octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. Around 300 species are recognised, and the order is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids.', 'The octopus is a soft-bodied, eight-limbed mollusc of the order Octopoda. Around 300 species are recognised, and the order is grouped within the class Cephalopoda with squids, cuttlefish, and nautiloids. Like other']}}]}]