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': 'Pernicious anaemia is associated with the deficiency of: \nSelect and explain. \nA. Folic acid, B. Vitamin B1, C. Vitamin B6, D. Vitamin B12', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]