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
[{'content': 'Radiological feature of Pneumothorax on USG \nSelect and explain. \nA. Lung sliding sign, B. Sea shore sign, C. B Lines, D. Stratosphere sign', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Lung sliding sign & Sea shore sign - Normal lung.\nB lines - Comet tail artefact below the pleura.', 'role': 'assistant'}]