This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S, Subject name: Pediatrics
Under the Jones criteria, which one of the following is a major criterion for the diagnosis of acute rheumatic fever? 
Select and explain. 
A. Elavated acute -phase reactants, B. Elevated ASO titer, C. Increased PR interval, D. Carditis
D: Carditis
Answer: D: Carditis 
Explanation: Carditis is a jones major criteria. Ref : Ghai essential of pediatrics, eighth edition, p.no:434