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
Hemiazygous vein crosses left to right at the level 
Select and explain. 
A. T8, B. T10, C. T12, D. T6
A: T8
Answer: A: T8 
Explanation: Hemiazygos vein crosses from left to right at the level of T8, after piercing the left crus of diaphragm while ascending.