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: Medicine
[{'content': 'Duration of pain is angina is - \nSelect and explain. \nA. 2-5 mins, B. 5-30 mins, C. 30-60 mins, D. > 1 hour', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]