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': 'Which of the following is derived from ectoderm- \nSelect and explain. \nA. Epithelium of iris, B. Ciliary muscles, C. Vascular endothelium, D. Sclera', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans-A', 'role': 'assistant'}]