This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intra Uterine Growth Restriction, Intrapaum and Antepaum Fetal Surviellance, Subject name: Gynaecology & Obstetrics
[{'content': 'Periconceptional use of the following agent leads to reduced incidence of neural tube defects \nSelect and explain. \nA. Folic acid, B. Iron, C. Calcium, D. Vitamin A', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Women should begin taking folic acid supplements before becoming pregnant and continue taking the supplements of at least 0.4 mg/day throughout the first trimester to reduce the risk of neural tube defects. It has been shown to reduce the occurrence and recurrence of neural tube defects . For low-risk women, folic acid supplementation of 400 micrograms per day currently is recommended For women at high risk of NTDs or who have had a previous pregnancy with an NTD, folic acid supplementation of 4 mg per day is recommended.', 'role': 'assistant'}]