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: Medicine
[{'content': 'Which of the following pathological agents are implicated in pseudogout? \nSelect and explain. \nA. Sodium monourate, B. Calcium oxalate, C. Calcium pyrophosphate, D. Sodium pyrophosphate', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pseudogout is a result of synovitis caused by calcium pyrophosphate crystals.', 'role': 'assistant'}]