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
Which of the following pathological agents are implicated in pseudogout? 
Select and explain. 
A. Sodium monourate, B. Calcium oxalate, C. Calcium pyrophosphate, D. Sodium pyrophosphate
C: Calcium pyrophosphate
Answer: C: Calcium pyrophosphate 
Explanation: Pseudogout is a result of synovitis caused by calcium pyrophosphate crystals.