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: Pathology
[{'content': 'Zellballen pattern is seen in \nSelect and explain. \nA. Paragangliomas, B. Pheochromocytom, C. Carotid by tumor, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer- D. All of the above', 'role': 'assistant'}]