Question: who won the oscar for best actor in 1997
[{'answer': 'Jack Nicholson', 'provenance': [{'wikipedia_id': '507423', 'title': '70th Academy Awards', 'start_paragraph_id': 5, 'start_character': 415, 'end_paragraph_id': 5, 'end_character': 429, 'bleu_score': 1.0, 'section': 'Section::::Winners and nominees.\n'}]}]