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
A boy is suffering from acute pyelonephritis 
Select and explain. 
A. WBC casts, B. Leucocyte esterase test, C. Nitrite, D. Bacteria in gram stain
A: WBC casts
Answer: A: WBC casts 
Explanation: Ans. a. WBC casts