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: Surgery
USG - KUB in evaluation of carcinoma prostate is not useful for 
Select and explain. 
A. LN involvement, B. Residual volume, C. Biopsy, D. Hydronephrosis
C: Biopsy
Answer: C: Biopsy 
Explanation: Biopsy is taken from transrectal ultrasound (TRUS).