Question: who played luke skywalker in empire strikes back
[{'answer': 'Mark Hamill', 'provenance': [{'wikipedia_id': '53964', 'title': 'The Empire Strikes Back', 'start_paragraph_id': 1, 'start_character': 405, 'end_paragraph_id': 1, 'end_character': 416, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]