This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': 'Paradoxical breathing is seen in \nSelect and explain. \nA. Pneumonia, B. Pneumothorax, C. Atelectasis, D. Flial chest', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Two of the symptoms of flail chest are chest pain and shoness of breath. It occurs when multiple adjacent ribs are broken in multiple places, separating a segment, so a pa of the chest wall moves independently. This so-called "paradoxical breathing" is painful and increases the work involved in breathing Ref Davidson 23rd edition pg 579', 'role': 'assistant'}]