This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Larynx, Subject name: ENT
[{'content': 'All of the following laryngeal muscles are adductors of vocal cord except: \nSelect and explain. \nA. Lateral cricoarytenoid, B. Posterior cricoarytenoid, C. Thyroarytenoid, D. Oblique arytenoid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Posterior cricoarytenoid is abductor of the vocal cord. In fact this is the only abductor muscle of the larynx. Lateral cricoarytenoid, thyroarytenoid, oblique arytenoid and transverse arytenoid are adductors of vocal cord.', 'role': 'assistant'}]