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
The best way to diagnose the degree of placenta pre is 
Select and explain. 
A. Trans vaginal sonography, B. Double set-up examination, C. Observation during C.S., D. Examination of placenta after delivery
A: Trans vaginal sonography
Answer: A: Trans vaginal sonography 
Explanation: Trans vaginal sonography