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
For Carcinoma of the prostate the commonest site is ? 
Select and explain. 
A. Anterior zone, B. Peripheral zone, C. Central zone, D. Transitional zone
B: Peripheral zone
Answer: B: Peripheral zone 
Explanation: Ans. is 'b' ie. Peripheral zone