This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal tract, Subject name: Pharmacology
[{'content': 'Which of the following drugs is not used for H.pylori treatment? \nSelect and explain. \nA. Oxytetracycline, B. Bismuth compounds, C. Amoxicillin, D. Omeprazole', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (ref :KDT 6/e p637)', 'role': 'assistant'}]