Question: who won the acc basketball tournament last year
[{'answer': 'Duke', 'provenance': [{'wikipedia_id': '51590299', 'title': "2017 ACC Men's Basketball Tournament", 'start_paragraph_id': 1, 'start_character': 224, 'end_paragraph_id': 1, 'end_character': 228, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '51590299', 'title': "2017 ACC Men's Basketball Tournament", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 415, 'bleu_score': 0.9247765631544721, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6835782869633874085}, 'section': 'Section::::Abstract.'}]}]