Question: who has been the longest reigning british monarch
[{'answer': 'Elizabeth II', 'provenance': [{'wikipedia_id': '1550265', 'title': 'List of monarchs in Britain by length of reign', 'start_paragraph_id': 2, 'start_character': 6, 'end_paragraph_id': 2, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1550265', 'title': 'List of monarchs in Britain by length of reign', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 278, 'bleu_score': 0.9560167778278961, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14646503300588531213}, 'section': 'Section::::Abstract.'}]}]