This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Joint disorders, Subject name: Orthopaedics
[{'content': 'A 65 years old lady presented with a swollen and painful knee. On examination, she was found to have grade III osteoahritic changes. What is the best course of action? \nSelect and explain. \nA. Conservative management, B. Ahroscopic washing, C. Paial knee replacement, D. Total knee replacement', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ref : maheswari 9th ed', 'role': 'assistant'}]