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
The most common cause of laryngeal stridor in a 60-year old male is: 
Select and explain. 
A. Nasopharyngeal carcinoma, B. Thyroid carcinoma, C. Foreign body aspiration, D. Carcinoma larynx
D: Carcinoma larynx
Answer: D: Carcinoma larynx 
Explanation: Most common cause for stridor in 60 years old male will be carcinoma larynx as carcinoma larynx occurs in males (predominantly) at the age of 40-70 years. Most common and earliest symptom of subglottic cancer is stridor. Nasopharyngeal cancer does not lead to stridor Thyroid cancer causes stridor rarely.