Question: who played boo radley in to kill a mockingbird
[{'answer': 'Robert Duvall', 'provenance': [{'wikipedia_id': '4607980', 'title': 'To Kill a Mockingbird (film)', 'start_paragraph_id': 1, 'start_character': 304, 'end_paragraph_id': 1, 'end_character': 317, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]