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': 'Hyperanslucency of lung unilaterally is seen on all except : \nSelect and explain. \nA. Pneumothorax, B. Resection of mammary gland, C. Pulm a. obstruction, D. Pneumonectomy', 'role': 'user'}, {'content': 'Answer: D \nExplanation: D i.e. Pneumonectomy Pulmonary agenesisQ & PneumonectomyQ are the causes of radiopaque lung with I/L mediastinal shiftQ. Pulmonary aery obstruction (i.e. Pulmonary embolism) l/t radiolucent lungQ.', 'role': 'assistant'}]