This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Hematology, Subject name: Pharmacology
Megaloblastic anemia is caused by all EXCEPT: 
Select and explain. 
A. Aspirin, B. primidone, C. Methotrexate, D. N2O
A: Aspirin
Answer: A: Aspirin 
Explanation: Methorexate can induce folate deficiency. Prolonged N2O anesthesia has the potential to depress bone marrow and cause peripheral neuropathy. Primidone is similar to phenytoin that is induces folate deficiency. From medical pharmacology padmaja 4th edition Page no 331 and Essential of medical pharmacology K D Tripati 7th edition page no 378