This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumothorax, Subject name: Medicine
[{'content': 'A 43-year-old 190 cm man post a flight to Chennai presents with left-sided chest discomfo and dyspnoea. On chest X-ray, there is a small area devoid of lung markings in the apex of the left lung. Diagnosis is? \nSelect and explain. \nA. Spontaneous pneumothorax, B. Myocardial infarction, C. Acute cor- pulmonale, D. Aoic dissection', 'role': 'user'}, {'content': 'Answer: A \nExplanation: 1. 190 cm man- Marfan syndrome 2. Devoid of lung margin, absent breath sounds- Pneumothorax 3. Aoic dissection- typical interscapular severe pain 4. Acute Cor pulmonary ruled out there is no history of ohopedic implant surgery, long flight', 'role': 'assistant'}]