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
After coming head of breech will have difficulty in delivery in all of the following conditions except: 
Select and explain. 
A. Hydrocephalus, B. Placenta previa, C. Incomplete dilation of cervix, D. Extension of head
B: Placenta previa
Answer: B: Placenta previa 
Explanation: None