This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Surgery
Characteristic of H. Pylori is 
Select and explain. 
A. Doesn't affect normal duodenal mucosa, B. Impoant cause for gastric ulcer, C. Protozoa, D. Antibiotics not useful
A: Doesn't affect normal duodenal mucosa
Answer: A: Doesn't affect normal duodenal mucosa 
Explanation: Normal duodenum cannot harbour H pylori, duodenum with gastric metaplasia can very well get infected by H pylori which explains why it is involved in duodenal ulcer. It is a gram-negative spiral like flagellated organism, it is most common cause of duodenal ulcer (95%), triple regime including clarithromycin - metronidazole - omeprazole is used for its treatment Reference SRB edition :5 page : 819, 820