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: Unknown
[{'content': "Gleason's classification used for \nSelect and explain. \nA. Carcinoma breast, B. Carcinoma prostate, C. Carcinoma pancreas, D. Carcinoma rectum", 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Carcinoma Prostate) (699- Basic robbins 8th)GLEASON - SYSTEM - Gleason grade has proved to correlate reasonably well with both the anatomic stage of prostatic carcinoma and the prognosis* Pancreatic cancer probably arise from precursor lesion (Pan INs) developing by a progressive accumulation of characteristic mutations of oncogenes (eg K-RAS) and tumor suppressor genes (eg P16, P53 and SMA D4)* Breast cancer - the majority are in the BRCA-1 and BRCA2 genes, less commonly in P53, PTEN or ATM genes', 'role': 'assistant'}]