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': 'Corneal transplantation: \nSelect and explain. \nA. Donor >60 years not allowed, B. Whole eye preserved in culture, C. Specular microscopy done for corneal endothelial count, D. HLA matching required', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Specular microscopy done for corneal endothelial count', 'role': 'assistant'}]