This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardiovascular system, Subject name: Radiology
[{'content': 'Which among the following is not a chest radiographic feature of left atrial enlargement? \nSelect and explain. \nA. Double left hea border, B. Elevated left main bronchus, C. Splaying of carina, D. Enlargement of left atrial appendage', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Double right hea border is seen in the left atrial enlargement not the Double left hea border ...Left atrial enlargement presents with elevation of left atrial bronchus ,Splaying or widening of carina , indentation and displacement of oesophagus posteriorly, Double right hea border and prominent left atrial appendage', 'role': 'assistant'}]