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': 'Primary Pulmonary T.B, true about -a) Cavitary lesionb) Pleural effusionc) Fibrocaseous lesiond) Phlyctenular keratitis \nSelect and explain. \nA. abc, B. acd, C. bcd, D. bd', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]