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: Surgery
[{'content': 'A patient with multiple injuries exhibit paradoxical chest movements during inspiration and expiration due to? \nSelect and explain. \nA. Pneumothorax, B. Flail chest, C. Cardiac temponade, D. Hemothorax', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]