This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'Thyroarytenoid muscle causes \nSelect and explain. \nA. Adduction of vocal cord, B. Tenses vocal cord, C. Relaxes vocal cord, D. Closes inlet of larynx', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Thyroarytenoid muscle is relaxor of vocal cord. Vocalis muscle which is medial fibre of thyroarytenoid, causes tension in anterior ⅓\xa0and relaxation in posterior ⅔\xa0of vocal cord.', 'role': 'assistant'}]