Question: when did the nba playoffs start in 2017
[{'answer': 'April 15 , 2017', 'provenance': [{'wikipedia_id': '50010152', 'title': '2017 NBA playoffs', 'start_paragraph_id': 1, 'start_character': 31, 'end_paragraph_id': 1, 'end_character': 46, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]