This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2017, Subject name: ENT
Abductor of vocal cord: 
Select and explain. 
A. Cricothyroid, B. Cricoarytenoid, C. Posterior cricoarytenoid, D. Lateral cricoarytenoid
C: Posterior cricoarytenoid
Answer: C: Posterior cricoarytenoid 
Explanation: INTRINSIC MUSCLES OF RESPIRATION: (a) Acting on vocal cords * Abductors: Posterior cricoarytenoid * Adductors: Lateral cricoarytenoid Interarytenoid (transverse arytenoid) Thyroarytenoid (external pa) * Tensors: Cricothyroid (Main tensor) Vocalis (internal pa of thyroarytenoid) (b) Acting on laryngeal inlet * Openers of laryngeal inlet: Thyroepiglottic (pa of thyroarytenoid) * Closers of laryngeal inlet: Interarytenoid (oblique pa). Aryepiglottic (posterior oblique pa of interarytenoids)