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: Ophthalmology
[{'content': 'Corneal epithelium is embryologically derived from: \nSelect and explain. \nA. Neural crest, B. Ectoderm, C. Mesoderm, D. Endoderm', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ectoderm', 'role': 'assistant'}]