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
Megaloblastic anaemia is caused by all EXCEPT : 
Select and explain. 
A. Aspirin, B. Primidone, C. Methotrexate, D. N2O
A: Aspirin
Answer: A: Aspirin 
Explanation: None