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: Unknown
Amniotic fluid alpha fetoprotein is raised by - 
Select and explain. 
A. Traumatic amniocentesis, B. Open neural tube defect, C. Intra uterine fetal death, D. None
B: Open neural tube defect
Answer: B: Open neural tube defect 
Explanation: Ans-B