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
Low molecular weight heparin inhibits 
Select and explain. 
A. Factor Xa, B. Factor Xa and II a, C. Factor II a, D. Factors II, VII, IX and X
B: Factor Xa and II a
Answer: B: Factor Xa and II a 
Explanation: Prophylaxis of neural tube defects require treatment with folic acid.
Methotrexate toxicity can be prevented by 5′-formyltetrahydrofolate (folinic acid).
Pernicious anemia requires the therapy with vitamin B12
Anemia associated with chronic renal failure is treated with erythropoietin.