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': 'Chest X-ray shows opacity after blunt trauma, most likely diagnosis is – \nSelect and explain. \nA. Haemothorax, B. Pneumothorax, C. Pneumonia, D. Pulmonary embolism', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Amongst the given options hemothorax and pneumonia (consolidation) produce opacity on chest X-ray. Pneumonia has nothing to do with blunt chest trauma, while hemothorax is common after blunt chest trauma. Therefore, best answer here is hemothorax.\nPneumothorax causes hypertranslucency (not opacity).', 'role': 'assistant'}]