This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Surfaces and Grooves, Subject name: Anatomy
[{'content': 'In PA view CXR, right border of the hea is contributed by- \nSelect and explain. \nA. pulmonary trunk, B. ascending aoa, C. left atrium, D. right ventricle', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Right border of hea SVC Right atrium IVC Ascending aoa', 'role': 'assistant'}]