This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abnormal labor, Subject name: Gynaecology & Obstetrics
Diameter of engagement In face presentation/ diameter In face presentation: 
Select and explain. 
A. Mentoveical, B. Submentoveical, C. Suboccipitobregmatic, D. Submentobregmatic
D: Submentobregmatic
Answer: D: Submentobregmatic 
Explanation: The engaging diameter is submentobregmatic (9.4cm).In face presentation,the biparietal diameter is 7cm behind the face unlike in veex,where it is only 3-4cm distant.The biparietal diameter will pass through the inlet only when the face is low down in the perineum (refer pgno:372 sheila textbook of obstetrics 2 nd edition)