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: Pathology
[{'content': 'Mucinous cystadenoma of the ovary arises - \nSelect and explain. \nA. From cystic teratoma, B. From surface coelomic epithelium, C. From sex cord stromal cells, D. From ectopic mucin secreting glands', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]