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
All the following are true about diploic vein except 
Select and explain. 
A. Lined by single Layer of endothelium suppod by elastic tissue, B. Present in cranial bones, C. Valveless/thin walled, D. Develop by 8th week of IUL
D: Develop by 8th week of IUL
Answer: D: Develop by 8th week of IUL 
Explanation: D i.e., Develops by 8th week of IUL The skull is unilamellar at bih with out any diploe and diploic veins which sta to develop at around 2 years after bih.