This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Anatomy
In Genitourinary TB, True is - 
Select and explain. 
A. Sterile pyuria is consistent finding, B. AFB in early morning sample is always positive, C. MC site is pelvis, D. Commonest cause of pyelonephritis
A: Sterile pyuria is consistent finding
Answer: A: Sterile pyuria is consistent finding 
Explanation: Sterile pyuria is the rule" - But about 15-20% of patients with tuberculosis have a secondary pyogenic infection, obscuring the clue - sterile pyuria. The tubercle bacilli can be identified on AFB staining of 24 hr urine specimen or the first-morning urine sample collected on 3 successive days." AFB staining is positive in about 60% of cases - Smith' Urology Most common site of genitourinary tuberculosis is - kidney The commonest cause of pyelonephritis is - E. coli Ref : Smith's Urology 17/e p195, 219