This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Physiology
[{'content': 'The most common site of ectopic pheochromocytoma is \nSelect and explain. \nA. Bladder, B. Filum terminale, C. Celiac plexus, D. Organ of Zuckerkandl', 'role': 'user'}, {'content': "Answer: B \nExplanation: Pheochromocytoma is a chromaffin cell tumor commonly located at adrenal medulla. Ectopic pheochromocytoma (EP) is considered as pheochromocytomalocated at extra-adrenal site, which usually lies at para-aoic region Ref ganong's review of medical physiology 25e", 'role': 'assistant'}]