Question: who starred in guess who's coming to dinner
[{'answer': 'Spencer Tracy', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 1, 'start_character': 145, 'end_paragraph_id': 1, 'end_character': 158, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Sidney Poitier', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 1, 'start_character': 160, 'end_paragraph_id': 1, 'end_character': 174, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Katharine Hepburn', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 1, 'start_character': 180, 'end_paragraph_id': 1, 'end_character': 197, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Katharine Houghton', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 1, 'start_character': 228, 'end_paragraph_id': 1, 'end_character': 246, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Beah Richards', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 22, 'start_character': 12, 'end_paragraph_id': 22, 'end_character': 25, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}, {'answer': 'Roy E. Glenn', 'provenance': [{'wikipedia_id': '70647', 'title': "Guess Who's Coming to Dinner", 'start_paragraph_id': 23, 'start_character': 12, 'end_paragraph_id': 23, 'end_character': 23, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}]