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': 'Sclera is weakest at all of the following sites except: \nSelect and explain. \nA. Apex, B. Limbus, C. Anteriorly, D. Posteriorly', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Posteriorly', 'role': 'assistant'}]