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: Pathology
[{'content': 'Which of the following is not related with carcinoma stomach - \nSelect and explain. \nA. Blood Group O, B. Blood group A, C. Smoked fish, D. Nitrosoamines', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]