This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bacteria, Subject name: Microbiology
[{'content': 'About Helicobacter pylori, all are true except: \nSelect and explain. \nA. Is a Gram -ve spiral bacteria, B. Uncommon in undeveloping Asian countries, C. Urea breath test +ve, D. Associated with duodenal ulcer', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans is 'b' i.e., Uncommon in undeveloping Asian countries (Ref: Harrison, 17th/e, p.946,19th/e, p. 1038; Ananthanarayan, 9th/e, p. 400)Approximately 85% of developing countries are affected by H. pylori.", 'role': 'assistant'}]