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
Fouth stage of labour i.e. observation of patient after delivery of placenta is defined as period of___________after delivery: 
Select and explain. 
A. 1 hour, B. 2 hour, C. 3 hour, D. 4 hour
A: 1 hour
Answer: A: 1 hour 
Explanation: 1 hour