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: Dental
Folic acid deficiency is precipitated by: 
Select and explain. 
A. Aspirin, B. Ranitidine, C. Cyclosporin, D. Phenytoin
D: Phenytoin
Answer: D: Phenytoin 
Explanation: None