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 of the following finding on MR imaging distinguishes vaginal atresia from mullerian agenesis 
Select and explain. 
A. Amount of upper vaginal dilatation, B. Presence of cervix, C. Length of atresia, D. Hymeneal ring
B: Presence of cervix
Answer: B: Presence of cervix 
Explanation: Presence of cervix distinguishes vaginal atresia from mullerian agenesis.