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': '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: Some epithelia derived from ectoderm- the epithelium of the skin , hair follicles, sweat glands, sebaceous glands, and mammary glands - the epithelium over cornea and conjunctiva, external acoustic meatus and the outer surface of the tympanic membrane- the epithelium of some pa of the mouth, the lower pa of the anal canal, terminal pa of the male urethra, pas of the female external genitaliaRef: Human Embryology; Inderbir Singh; Tenth Edition; Page No: 95', 'role': 'assistant'}]