Question: who plays the ghost in a ghost story
[{'answer': 'Casey Affleck', 'provenance': [{'wikipedia_id': '52351891', 'title': 'A Ghost Story', 'start_paragraph_id': 1, 'start_character': 104, 'end_paragraph_id': 1, 'end_character': 117, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '52351891', 'title': 'A Ghost Story', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 284, 'bleu_score': 0.9603762111511761, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17192914474975485949}, 'section': 'Section::::Abstract.'}]}]