This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head and neck, Subject name: Anatomy
Which muscle is an abductor of the vocal cords? 
Select and explain. 
A. Transverse arytenoid, B. Oblique arytenoid, C. Lateral thyroarytenoid, D. Posterior Cricoarytenoid
D: Posterior Cricoarytenoid
Answer: D: Posterior Cricoarytenoid 
Explanation: movement and muscles 1.Elevation of larynx: thyrohyoid.mylohyoid 2. Depression of larynx: .sternothyroid, sternohyoid. 3. Opening inlet of larynx: thyroepiglottic. 4. Closing inlet of larynx: aryepiglottic 5. Abductor of vocal cords: posterior cricoarytenoid only 6. Adductor of vocal cords: lateral cricoarytenoid transverse and oblique arytenoids Ref BDC volume 3, 6th edition pg 258