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 of the following veins lack valves except 
Select and explain. 
A. Femoral vein, B. Poal vein, C. IVC, D. Dural venous sinuses
A: Femoral vein
Answer: A: Femoral vein 
Explanation: Veins which do not have valves are:IVCSVCHepatic, ovarian, uterine, renal, emissary, cerebral, pulmonary, and umbilical veinsPoal venous system is a valveless system