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
The most important use of transrectal ultarsonography (TRUS) is for - 
Select and explain. 
A. Screening for Ca prostate, B. Distinguishing prostate cancer from BPH, C. Systematic prostate biopsy in suspected prostate cancer, D. Guiding transurethral resection of prostate cancer
C: Systematic prostate biopsy in suspected prostate cancer
Answer: C: Systematic prostate biopsy in suspected prostate cancer 
Explanation: Uses of TRUS in CA prostate
• To guide biopsy
• To guide therapy