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': 'In lung X-ray, heterogenous shadow is due to: \nSelect and explain. \nA. Haemangiorma, B. Pulmonary infarction, C. Metastatic lesion, D. TB', 'role': 'user'}, {'content': 'Answer: C \nExplanation: C i.e. Metastasis Pulmonary metastasis is radiologically hetrogenousQ due to occurance of cavitation (more common in squamous cell carcinoma) & calcification (most often in osteogenic SAQ & rarely in chondrosarcoma.', 'role': 'assistant'}]