This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Pathology
[{'content': 'Colon carcinogenesis is associated with all except \nSelect and explain. \nA. APC, B. kRAS, C. B-catenin, D. None', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Etiology & Risk factors of Ca Colon 1)DIETARY FACTORS Low intake of dietary fibres High intake of carbohydrates and fat Diet deficient of cruciferous vegetables and vitamin A 2) PROTECTIVE EFFECT OF ASPIRIN 3) HNPCC 4) RISK FACTORS- age above 50, family history of colonic cancer, prior colorectal cancer, inflammatory bowel disorders, physical inactivity, smoking, alcohol consumption 5) GENETIC PATHWAY APC-beta catenin pathway K-RAS mutation SMAD2 and SMAD4 mutation Mutation of p53 Activation of telomerase Microsatellite instability pathway GENERAL AND SYSTEMIC PATHOLOGY RAMDAS NAYAK FIRST EDITION PAGE: 418,419', 'role': 'assistant'}]