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
Atonic post paum hemorrhage occurs in all except : 
Select and explain. 
A. Multiple pregnancy, B. Hydramnios, C. Erythroblastosis fetalis, D. Prolonged labour
C: Erythroblastosis fetalis
Answer: C: Erythroblastosis fetalis 
Explanation: Erythroblastosis fetalis