This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General obstetrics, Subject name: Gynaecology & Obstetrics
Monochorionic monoamniotic twin occurs if division occurs: 
Select and explain. 
A. Before 24 hours, B. 1-4 days, C. 4-8 days, D. > 8 days
D: > 8 days
Answer: D: > 8 days 
Explanation: If the division occur after eight day of feilisation,when the amniotic cavity has already formed,a monoamniotic-monochorionic twin develops. Reference:DC Dutta&;s textbook of obstetrics,8th edition, page no:233. <\p>