This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immune system, Subject name: Medicine
Most specific diagnostic finding in gout is - 
Select and explain. 
A. Uric acid crystals in urine, B. Raised serum uric acid, C. Presence of calcium pyrophosphate crystals in synol fluid, D. Presence of monosdium crystals in synol fluid
D: Presence of monosdium crystals in synol fluid
Answer: D: Presence of monosdium crystals in synol fluid 
Explanation: The diagnosis of gout can be confirmed by the identification of urate crystals in the aspirate from a joint, bursa or tophus . In acute gout, the synol fluid may beturbid due to an elevated neutrophil count. In chronic gout, the appearance is more variable but occasionally the fluid appears white due to the presence of urate crystals. Between attacks, aspiration of an asymptomatic first MTP joint or knee may still reveal crystals. Ref Davidsons 23e p1015