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: Unknown
[{'content': 'Lens is derived from? \nSelect and explain. \nA. Endoderm, B. Surface ectoderm, C. neural crest cells, D. none of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ans. (b) Surface ectodermRef : Yanoff and ducker-ophthalmology 2/e, p 22-23, parson 20/ey p 5, Khurana 4/e, p 10', 'role': 'assistant'}]