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: ENT
Cricothyroid muscle is supplied by: 
Select and explain. 
A. Superior laryngeal nerve, B. External laryngeal nerve, C. Vagus nerve, D. Glossopharyngael nerve
A: Superior laryngeal nerve
Answer: A: Superior laryngeal nerve 
Explanation: All the muscles which play any role in movement of vocal cord are supplied by recurrent laryngeal nerve except the cricothyroid muscle which receives its innervation from the external laryngeal nerve - a branch of superior laryngeal nerve.