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: Pharmacology
[{'content': "Large bilateral painless effusions of the knees occurring in late congenital syphilis in patients between ages 8 to 18 are designated as \nSelect and explain. \nA. Clutton's joints, B. Ramsey's joints, C. Charcot's joints, D. Mercer's joints", 'role': 'user'}, {'content': 'Answer: A \nExplanation: .', 'role': 'assistant'}]