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 clit: \nSelect and explain. \nA. Enlargement of left atrial appendage, B. Azygous vein enlargement, C. Coronary aery aneurysm, D. Pulmonary edema', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Enlargement of left atrial appendage Left hea border on chest X-ray PA view is fonned by- Aoic Knuckle, Pulmonary Conus, Left atrial Appendage and Left Ventricle. So left sided cardiac bulge is seen in enlargement of left atrial appendageQ. Mn- "AK PC LAAV = cb Personal computer LoVe" forms left hea border.', 'role': 'assistant'}]