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: Gynaecology & Obstetrics
[{'content': 'Neural tube defect is due to deficiency of: March 2012 \nSelect and explain. \nA. Vitamin B12, B. Thiamine, C. Folic acid, D. Riboflavin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans: C i.e. Folic acid Folic acid supplementation beginning 1 month before conception to about 12 weeks of pregnancy has reduced the incidence of neural tube defects significantly (85%).', 'role': 'assistant'}]