Question: who has the best selling single of all time
[{'answer': 'Bing Crosby', 'provenance': [{'wikipedia_id': '7577577', 'title': 'List of best-selling singles', 'start_paragraph_id': 2, 'start_character': 87, 'end_paragraph_id': 2, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '7577577', 'title': 'List of best-selling singles', 'start_paragraph_id': 2, 'start_character': 20, 'end_paragraph_id': 2, 'end_character': 882, 'bleu_score': 0.9337710621278871, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1970573796488359182}, 'section': 'Section::::Abstract.'}]}]