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
[{'content': 'Which of the following is the anterior relation to first pa of duodenum ? \nSelect and explain. \nA. root of mesentary, B. superior mesenteric vessels, C. transverse mesocolon, D. gallbladder', 'role': 'user'}, {'content': "Answer: D \nExplanation: Visceral Relations of 1st pa of duodenum Anteriorly: 1)Quadrate lobe of liver, and 2) gall bladder. Ref : B D Chaurasia's Human Anatomy , seventh edition , voulme 2 , pg. no., 286 ( Fig. 20.8a )", 'role': 'assistant'}]