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
Which among the following is the earliest to be detected by an antenatal USG? 
Select and explain. 
A. Anencephaly, B. Down's syndrome, C. Gender, D. Cleft palate
A: Anencephaly
Answer: A: Anencephaly 
Explanation: Anencephaly can be detected as early as 10 weeks of pregnancy and the diagnosis is 100% accurate.