This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Ophthalmology
[{'content': 'which layer of cornea helps in maintaining hydration OF stroma of cornea \nSelect and explain. \nA. Descement membrane, B. Endothelium, C. Epithelium, D. stroma', 'role': 'user'}, {'content': 'Answer: B \nExplanation: REF : AK KHURANA 7TH ED', 'role': 'assistant'}]