Question: who played the lead role in to kill a mockingbird
[{'answer': 'Gregory Peck', 'provenance': [{'wikipedia_id': '4607980', 'title': 'To Kill a Mockingbird (film)', 'start_paragraph_id': 1, 'start_character': 198, 'end_paragraph_id': 1, 'end_character': 210, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]