Question: who composed the original story of mahabharata in oral form
[{'answer': 'Vyāsa', 'provenance': [{'wikipedia_id': '19643', 'title': 'Mahabharata', 'start_paragraph_id': 3, 'start_character': 68, 'end_paragraph_id': 3, 'end_character': 73, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '19643', 'title': 'Mahabharata', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 551, 'bleu_score': 0.8418814923594741, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14674850403354219359}, 'section': 'Section::::Abstract.'}]}]