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
[{'content': 'The following muscle is an opener of the glottis \nSelect and explain. \nA. Lateral cricoarytenoid, B. Posterior cricoarytenoid, C. Transverse arytenoid, D. Inter arytenoids', 'role': 'user'}, {'content': 'Answer: B \nExplanation: 1. Muscles which abduct the vocal cords: only posterior cricoarytenoids( safety muscles of larynx) 2. Muscles which adduct the vocal cords: * lateral cricoarytenoids * transverse aenoid * cricothyroid *thyroarytenoids 3. Muscles which tense the vocal cords: cricothyroid 4.muscles which relax the vocal cords: * thyroarytenoids * vocalis 4. Muscles which close the inlet of the larynx * oblique arytenoids * aryepiglottic 5.muscles which open the inlet of larynx : Thyroepiglotticus Ref BDC volume 3; 6th edition pg 258', 'role': 'assistant'}]