This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urethra & Penis, Subject name: Surgery
Because of positive biopsy findings and negative workup, he undergoes a radical prostatectomy. The pathology report reveals Gleason score 9/10 and involvement of several pelvic lymph nodes. Which is the most likely site for prostatic cancer metastasis? 
Select and explain. 
A. Liver, B. Kidney, C. Lung, D. Bone
D: Bone
Answer: D: Bone 
Explanation: Bone metastasis is a characteristic feature of prostatic cancer. The lesions are typically osteoblastic on x-ray, and the serum acid phosphatase level becomes elevated.