Question: who played the title role in the film superman
[{'answer': 'Christopher Reeve', 'provenance': [{'wikipedia_id': '362719', 'title': 'Superman (1978 film)', 'start_paragraph_id': 1, 'start_character': 149, 'end_paragraph_id': 1, 'end_character': 166, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]