Question: who sings when you back that thing up
[{'answer': 'Juvenile', 'provenance': [{'wikipedia_id': '2924733', 'title': 'Back That Thang Up', 'start_paragraph_id': 1, 'start_character': 114, 'end_paragraph_id': 1, 'end_character': 122, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '2924733', 'title': 'Back That Thang Up', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 444, 'bleu_score': 0.7762478681407871, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17446379204121495890}, 'section': 'Section::::Abstract.'}]}]