Question: who played prince's father in purple rain
[{'answer': 'Clarence Williams III', 'provenance': [{'wikipedia_id': '226331', 'title': 'Purple Rain (film)', 'start_paragraph_id': 12, 'start_character': 12, 'end_paragraph_id': 12, 'end_character': 33, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'provenance': [{'wikipedia_id': '226331', 'title': 'Purple Rain (film)', 'start_paragraph_id': 12, 'start_character': 0, 'end_paragraph_id': 12, 'end_character': 62, 'bleu_score': 0.7598356856515921, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9274800677531711454}, 'section': 'Section::::Cast.\n'}]}]