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: Radiology
[{'content': 'Left sided cardiac bulge seen on chest X-ray is/are d/t to – \nSelect and explain. \nA. Enlargement of left atrial appendage, B. Azygous vein enlargement, C. Coronary artery aneurysm, D. Pulmonary edema', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]