This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
Thyroarytenoid muscle causes 
Select and explain. 
A. Adduction of vocal cord, B. Tenses vocal cord, C. Relaxes vocal cord, D. Closes inlet of larynx
C: Relaxes vocal cord
Answer: C: Relaxes vocal cord 
Explanation: Thyroarytenoid muscle is relaxor of vocal cord. Vocalis muscle which is medial fibre of thyroarytenoid, causes tension in anterior ⅓ and relaxation in posterior ⅔ of vocal cord.