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
Earliest detectable congenital malformation by USG 
Select and explain. 
A. Anencephaly, B. Spina bifida, C. Meningocoele, D. cystic hygroma
A: Anencephaly
Answer: A: Anencephaly 
Explanation: None