This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: miscellaneous, Subject name: Pathology
[{'content': 'Zellballen pattern on histopathology is observed in?- \nSelect and explain. \nA. GIST, B. Astrocytorna, C. Carotid body tumor, D. Retinoblastoma', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Zellballen pattern on histopathology is observed in Paraganglioma or Carotid body tumors. Zellenbalen- composed to nests of polygonal chief cells. Robbins basic pathology. 7th edition. page no. 789.', 'role': 'assistant'}]