This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory, Subject name: Medicine
[{'content': 'A 25-year-old man presented to the emergency medicine department with acute onset sharp pain and dyspnea. His chest X-ray (CXR) is given here. What is the diagnosis? \nSelect and explain. \nA. Pleural effusion, B. Pulmonry embolism, C. Hydropneumothorax, D. Spontaneous pneumothorax', 'role': 'user'}, {'content': 'Answer: D \nExplanation: ANS. D', 'role': 'assistant'}]