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: Social & Preventive Medicine
[{'content': 'Among the following, which one is the absolute contraindication for combined oral contraceptive pills - \nSelect and explain. \nA. Diabetes mellitus, B. Migraine, C. Previous history of thrombo-embolism, D. Heart dsease', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]