This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Gynaecology & Obstetrics
Prolonged latent phase in nullipara is defined as one exceeding 
Select and explain. 
A. 10 hours, B. 14 hours, C. 18 hours, D. 20 hours
D: 20 hours
Answer: D: 20 hours 
Explanation: A prolonged latent phase was defined as one exceeding 20 hours in the nullipara and 14 hours in the multiparous women.(Ref: William's Obstetrics; 25th edition)