This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Labour - normal, abnormal, malposition, malpresentation and their management, Subject name: Gynaecology & Obstetrics
The following abdominal palpation at 18 weeks of gestation is said to be: 
Select and explain. 
A. External ballottement, B. Internal ballottement, C. Fouh leopold grip, D. Palmer's sign
A: External ballottement
Answer: A: External ballottement 
Explanation: External ballottement - Usually elicited as early as 20th week when the fetus is relatively smaller than the volume of the amniotic fluid. It is difficult to elicit in obese patients and in cases with scanty liquor amnii. It is best elicited in breech presentation with the head at the fundus.