This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastro-Intestinal Tract, Subject name: Pharmacology
[{'content': 'Anti-helicobacter pylori drugs are all of the following except:- \nSelect and explain. \nA. Clarithromycin, B. Amoxicillin, C. Metronidazole, D. Ofloxacin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Antimicrobials effective against H. pylori are :- Metronidazole/tinidazole Amoxicillin Clarithromycin Tetracycline Colloidal bismuth subcitrate', 'role': 'assistant'}]