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: Pharmacology
[{'content': 'Which of the following drugs should not be administered concomitantly with warfarin as it decreases the effect of oral anticoagulants ? \nSelect and explain. \nA. Broad spectrum antibiotic, B. Cimetidine, C. Aspirin, D. Oral contraceptive', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]