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: Radiology
Radiological feature of Pneumothorax on USG 
Select and explain. 
A. Lung sliding sign, B. Sea shore sign, C. B Lines, D. Stratosphere sign
D: Stratosphere sign
Answer: D: Stratosphere sign 
Explanation: Lung sliding sign & Sea shore sign - Normal lung.
B lines - Comet tail artefact below the pleura.