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: Anatomy
[{'content': 'A lady presents with right knee swelling.Aspiration was done in which CPPD crystals were obtained.Next best investigation is \nSelect and explain. \nA. ANA, B. RF, C. CPK, D. TSH', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Secondary CPPD deposition is associated with hypothyroid,hence TSH level should be assessed. Other conditions: Hyperparathyroidism Hemochromatosis Hypophosphaemia Hypomagnesemia Diabetes', 'role': 'assistant'}]