Question: who achieved a victory at the battle of marathon
[{'answer': 'Greece', 'provenance': [{'wikipedia_id': '4806', 'title': 'Battle of Marathon', 'start_paragraph_id': 1, 'start_character': 85, 'end_paragraph_id': 1, 'end_character': 91, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]