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: Medicine
[{'content': 'Ellis curve is seen in \nSelect and explain. \nA. Pheumothorax, B. Pheumonia, C. Asthma, D. Pleural effusion', 'role': 'user'}, {'content': 'Answer: D \nExplanation: o On chest X-rays, pleural effusion presents as homogenous opacity.\no Typically this opacity has a fairly well defined concave upper edge, is higher laterally than medially and obscures the diaphragmatic shadow', 'role': 'assistant'}]