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
Closure of glottis is by all except 
Select and explain. 
A. Posterior cricoarytenoid, B. Lateral cricoarytenoid, C. Cricothyroid, D. Thyroarytenoid
A: Posterior cricoarytenoid
Answer: A: Posterior cricoarytenoid 
Explanation: 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