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
[{'content': 'Which of the following is related to third part of duodenum - \nSelect and explain. \nA. Portal vein, B. Head of pancreas, C. Hepatic artery, D. Superior mesenteric vein', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]