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: Surgery
[{'content': 'what is true about keloids \nSelect and explain. \nA. it appears immediately after surgery, B. it appears a few days after surgery, C. it is limited in its distribution, D. it is common in old people', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]