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: Microbiology
[{'content': 'True about H. pylori - \nSelect and explain. \nA. Seen in 85 to 90% cases of gastric ulcer, B. Seen in 20 to 25% cases of duodenal ulcer, C. Transmitted from man to man, feco-orally & by orogastric route, D. Common in adults of developing countries', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]