Question: who were the gods and goddesses who were considered the chthonic gods
[{'answer': 'Persephone', 'provenance': [{'wikipedia_id': '444886', 'title': 'Chthonic', 'start_paragraph_id': 3, 'start_character': 292, 'end_paragraph_id': 3, 'end_character': 302, 'bleu_score': 1.0, 'section': 'Section::::Chthonic cults.\n'}]}, {'answer': 'Hades', 'provenance': [{'wikipedia_id': '444886', 'title': 'Chthonic', 'start_paragraph_id': 3, 'start_character': 307, 'end_paragraph_id': 3, 'end_character': 312, 'bleu_score': 1.0, 'section': 'Section::::Chthonic cults.\n'}]}, {'provenance': [{'wikipedia_id': '444886', 'title': 'Chthonic', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 335, 'bleu_score': 0.962600167205617, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7792422055027823983}, 'section': 'Section::::Chthonic cults.\n'}]}]