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
Critical obstetric conjugate for trial of labour is: 
Select and explain. 
A. 8.5 cms, B. 9.0 cms, C. 9.5 cms, D. 10.0 cms
D: 10.0 cms
Answer: D: 10.0 cms 
Explanation: None