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
Patient underwent surgery at the lateral pa of the skull. Postoperatively patient had aspirations without voice change 
Select and explain. 
A. Vagus, B. RLN, C. Glossopharyngeal, D. SLN
D: SLN
Answer: D: SLN 
Explanation: Ans. D (Superior Laryngeal nerve)* Vagus, RLN involvement leads to hoarseness of the voice* SLN divide into internal and external laryngeal* External laryngeal nerve supplies only one muscle- cricothyroid - tensor* Internal laryngeal nerve- safety nerve of larynx- prevents aspiration and supplies supraglottic pa of larynx.