Question: who won the 2017 australian open womens single title
[{'answer': 'Serena Williams', 'provenance': [{'wikipedia_id': '52071277', 'title': "2017 Australian Open – Women's Singles", 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]