Question: who was the last ruler of the tang dynasty
[{'answer': 'Emperor Ai of Tang', 'provenance': [{'wikipedia_id': '43455', 'title': 'Tang dynasty', 'start_paragraph_id': 30, 'start_character': 555, 'end_paragraph_id': 30, 'end_character': 573, 'bleu_score': 1.0, 'section': 'Section::::History.:End of the dynasty.\n'}]}, {'provenance': [{'wikipedia_id': '43455', 'title': 'Tang dynasty', 'start_paragraph_id': 30, 'start_character': 442, 'end_paragraph_id': 30, 'end_character': 977, 'bleu_score': 0.5068055404750911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8419456882403216143}, 'section': 'Section::::History.:End of the dynasty.\n'}]}]