Question: who sings with keith urban on the fighter
[{'answer': 'Carrie Underwood', 'provenance': [{'wikipedia_id': '51032008', 'title': 'The Fighter (Keith Urban song)', 'start_paragraph_id': 1, 'start_character': 116, 'end_paragraph_id': 1, 'end_character': 132, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]