Question: who won dancing with the stars season 21
[{'answer': 'Bindi Irwin', 'provenance': [{'wikipedia_id': '46214776', 'title': 'Dancing with the Stars (American season 21)', 'start_paragraph_id': 2, 'start_character': 22, 'end_paragraph_id': 2, 'end_character': 33, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Derek Hough', 'provenance': [{'wikipedia_id': '46214776', 'title': 'Dancing with the Stars (American season 21)', 'start_paragraph_id': 2, 'start_character': 50, 'end_paragraph_id': 2, 'end_character': 61, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '46214776', 'title': 'Dancing with the Stars (American season 21)', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 927, 'bleu_score': 0.9877670085238551, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11965272639247156932}, 'section': 'Section::::Abstract.'}]}]