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
Zellballen pattern is seen in 
Select and explain. 
A. Paragangliomas, B. Pheochromocytom, C. Carotid by tumor, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Answer- D. All of the above