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
Anomaly scan is done at _______ weeks of gestation 
Select and explain. 
A. 16, B. 18, C. 20, D. 22
C: 20
Answer: C: 20 
Explanation: Anamoly scan is done at 18 - 20 weeks best done at 20 weeks.