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: Radiology
The earliest congenital malformation that can he detected on USG: 
Select and explain. 
A. Anencephaly, B. Hydrocephalus, C. Sacral agenesis, D. Down's syndrome
A: Anencephaly
Answer: A: Anencephaly 
Explanation: Ans. Anencephaly