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 vessel does not cross the midline of the body? 
Select and explain. 
A. Left gonadal vein, B. Left renal vein, C. Left brachiocephalic vein, D. Hemiazygous vein
A: Left gonadal vein
Answer: A: Left gonadal vein 
Explanation: The left gonadal vein drains into the left renal vein which crosses the midline to join inferior vena cava. All the other options (Left renal vein, left brachiocephalic vein and hemiazygous vein) cross the midline.