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
A 65 years old lady presented with a swollen and painful knee. On examination, she was found to have grade III osteoarthritic changes. What is the best course of action? 
Select and explain. 
A. Conservative management, B. Arthroscopic washing, C. Partial knee replacement, D. Total knee replacement
A: Conservative management
Answer: A: Conservative management 
Explanation: Grade I to III → Start with conservative treatment. If fails, surgery is indicated.
Grade IV & V → Total knee replacement is the treatment of choice.