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: Anatomy
Which of the following disappear in umbilical cord 
Select and explain. 
A. Left aery, B. Left vein, C. Right aery, D. Right aery
D: Right aery
Answer: D: Right aery 
Explanation: D. i.e. Right vein