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: Biochemistry
[{'content': 'Vitamin B12 deficiency has A/E \nSelect and explain. \nA. Folate trap, B. Decreased methyl malonyl CoA, C. SACD, D. Megaloblastic anemia', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Decreased methylmalonyl CoA', 'role': 'assistant'}]