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': 'Concomitant treatment with which of the following can cause OCP failure \nSelect and explain. \nA. Enalapril., B. Metformin, C. Ibuprofen, D. Rifampicin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Rifampicin', 'role': 'assistant'}]