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: Pathology
[{'content': 'Which of the following is the least common site of atherosclerotic lesions - \nSelect and explain. \nA. Aortic bifurcation, B. Pulmonary arterial trunk, C. Common carotid artery, D. Middle cerebral artery', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]