Question: who is regarded as the finest stringed instrument builder of all time
[{'answer': 'Antonio Stradivari', 'provenance': [{'wikipedia_id': '56455', 'title': 'Antonio Stradivari', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 18, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '56455', 'title': 'Antonio Stradivari', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 445, 'bleu_score': 0.717757746653603, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11581393925471178009}, 'section': 'Section::::Abstract.'}]}]