This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
Mediastinoscope can be visualize all of the following lymphnode except? 
Select and explain. 
A. Right paratracheal lymphnode, B. Aoo pulmonary window lymphnode, C. Anterior tracheal, D. Subcarinal
B: Aoo pulmonary window lymphnode
Answer: B: Aoo pulmonary window lymphnode 
Explanation: Mediastinoscopy is a surgical procedure used to obtain specimens from masses or nodes in the mediastinum.Suprasternal approach is commonly used for mediastinoscopy.Aoopulmonary lymph nodes are not accessible by this route and thus are commonly sampled by parasternal mediastinotomy (the Chamberlain procedure). Extended mediastinoscopy is a technique which allows access to the pre-aoic (station 6) and aoopulmonary window(station 5) lymph nodes.