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': 'Platypilea is seen in \nSelect and explain. \nA. Diaphragmatic palsy, B. Pleural effusion, C. pulmonary embolism, D. Lt atrial tumor', 'role': 'user'}, {'content': "Answer: B \nExplanation: platypnea ohodeoxia is typically an ove symptom when the patient's posture changes from the supine to the upright position. .Especially when a significant pleural ef- fusion (hydrothorax) is present, the intrathoracic effusion spreads diffusely over the posterior space of the thorax in the supine position. Ref Davidson 23rd edition pg 619", 'role': 'assistant'}]