Question: who won the us open golf last year
[{'answer': 'Brooks Koepka', 'provenance': [{'wikipedia_id': '16680797', 'title': 'List of U.S. Open (golf) champions', 'start_paragraph_id': 3, 'start_character': 472, 'end_paragraph_id': 3, 'end_character': 485, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]