Question: who is the captain of chennai super king
[{'answer': 'Mahendra Singh Dhoni', 'provenance': [{'wikipedia_id': '15829930', 'title': 'Chennai Super Kings', 'start_paragraph_id': 1, 'start_character': 612, 'end_paragraph_id': 1, 'end_character': 632, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '15829930', 'title': 'Chennai Super Kings', 'start_paragraph_id': 31, 'start_character': 0, 'end_paragraph_id': 31, 'end_character': 423, 'bleu_score': 0.535173585090832, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17019561814029245509}, 'section': 'Section::::Players.\n'}]}]