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: Surgery
Screening of prostate Ca is done by 
Select and explain. 
A. Transrectal USG, B. Digital rectal exam, C. PSA, D. CT scan
B: Digital rectal exam
Answer: B: Digital rectal exam 
Explanation: Screening for malignancy according to America cancer society Recommendations for early detection of cancer in Average - Risk, Asymptomatic individuals Cancer site : Prostate Population : Men aged >= 50 years Test or procedure : Digital rectal examination (DRE) and prostate specific antigen (PSA) test. Frequency : Offer PSA test and DRE annually, staing at age 50,for men who have life expectancy of atleast 10 years Ref: Harrison's 19th edition Pgno : 481