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: Orthopaedics
[{'content': 'Fluid accumulation in knee joint to elicit Bulge sign is \nSelect and explain. \nA. 15 ml, B. 30 ml, C. 45 ml, D. 100 ml', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]