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': 'Closure of glottis is by all except \nSelect and explain. \nA. Posterior cricoarytenoid, B. Lateral cricoarytenoid, C. Cricothyroid, D. Thyroarytenoid', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Posterior cricoarytenoid acts by abducting vocal cords. Lateral cricoarytenoid and Thyroarytenoids are adductors of vocal cords. Whereas Cricothyroid is tensor of vocal cords. Ref: Textbook of diseases of ENT, PL Dhingra, 7th edition, pg no. 320', 'role': 'assistant'}]