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': 'Avascular coat in the eye is – \nSelect and explain. \nA. Sclera, B. Cornea, C. Retina, D. Choroid', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Cornea is an avascular structure. Crystalline lens is also avascular.', 'role': 'assistant'}]