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: Pharmacology
[{'content': 'Low molecular weight heparin inhibits \nSelect and explain. \nA. Factor Xa, B. Factor Xa and II a, C. Factor II a, D. Factors II, VII, IX and X', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Prophylaxis of neural tube defects require treatment with folic acid.\nMethotrexate toxicity can be prevented by 5′-formyltetrahydrofolate (folinic acid).\nPernicious anemia requires the therapy with vitamin B12\nAnemia associated with chronic renal failure is treated with erythropoietin.', 'role': 'assistant'}]