This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
[{'content': 'Lens is derived from \nSelect and explain. \nA. Ectoderm, B. Endoderm, C. Mesoderm, D. Neuroectoderm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Unlike the rest of the eye, which is derived mostly from the neural ectoderm, the lens is derived from the surface ectoderm. ... As the placode continues to deepen, the opening to the surface ectoderm constricts and the lens cells forms a structure known as the lens vesicle. Latin: lens crystallin Function: Refract light', 'role': 'assistant'}]