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
All of the following are carcinogenic except 
Select and explain. 
A. H. pylori, B. Hepatitis B virus, C. E.B. virus, D. Campylobacter
D: Campylobacter
Answer: D: Campylobacter 
Explanation: None