Question: who played io in clash of the titans
[{'answer': 'Gemma Arterton', 'provenance': [{'wikipedia_id': '22358819', 'title': 'Clash of the Titans (2010 film)', 'start_paragraph_id': 14, 'start_character': 12, 'end_paragraph_id': 14, 'end_character': 26, 'bleu_score': 1.0, 'section': 'Section::::Cast.\n'}]}]