Question: who sings in the diet dr. pepper commercial
[{'answer': 'Justin Guarini', 'provenance': [{'wikipedia_id': '417943', 'title': 'Justin Guarini', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 14, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '417943', 'title': 'Justin Guarini', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 137, 'bleu_score': 0.593652497216493, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15287988902785424831}, 'section': 'Section::::Abstract.'}]}]