Question: name the world's largest riverine island formed by the brahmaputra
[{'answer': 'Mājuli or Majoli', 'provenance': [{'wikipedia_id': '881600', 'title': 'Majuli', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 16, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]