This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
A 43 year old man complains of abdominal pain just above his umbilicus. On examination , a tumor is found anterior to the IVC. Which of the following structures would most likely to be compressed by this tumor? 
Select and explain. 
A. Right sympathetic trunk, B. Left third lumbar aery, C. Third pa of the duodenum, D. Left renal aery
C: Third pa of the duodenum
Answer: C: Third pa of the duodenum 
Explanation: The third pa of the duodenum (transverse poion) crosses anterior to the IVC. The other structures do not cross the IVC anteriorly. Ref: Gray&;s Anatomy 41st edition Pgno: 1156