Question: who sang t r o u b l e
[{'answer': 'Elvis Presley', 'provenance': [{'wikipedia_id': '22648202', 'title': 'T-R-O-U-B-L-E (song)', 'start_paragraph_id': 1, 'start_character': 67, 'end_paragraph_id': 1, 'end_character': 80, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]