Question: in 550 bc which leader began the persian empire
[{'answer': 'Cyrus the Great', 'provenance': [{'wikipedia_id': '24187128', 'title': 'Persian Empire', 'start_paragraph_id': 4, 'start_character': 83, 'end_paragraph_id': 4, 'end_character': 98, 'bleu_score': 1.0, 'section': 'Section::::History.:Achaemenids.\n'}]}, {'provenance': [{'wikipedia_id': '24187128', 'title': 'Persian Empire', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 367, 'bleu_score': 0.8154934907711471, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 10710964165210357756}, 'section': 'Section::::History.:Achaemenids.\n'}]}]