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: Medicine
MIBG (metaiodobenzyl guanithidine) is analogue to: 
Select and explain. 
A. Epinephrine, B. Adenine, C. Norepinephrine, D. Guanine
C: Norepinephrine
Answer: C: Norepinephrine 
Explanation: Answer- (C) NorepinephrinePheochromocytoma can be localized using radioactive tracers including 131 I-or 123 l- metaiodobenzyl guanithidine (MIBG), 111 ln-somatostatin analogues, or 18 F-dopa (or dopamine) Positron-emission tomography (PET).