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 atrial enlargement is best seen with: \nSelect and explain. \nA. Chest X-ray AP view, B. Chest X-ray left lateral view, C. Barium swallow right anterior oblique view, D. Barium swallow left anterior oblique view', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. Barium swallow right anterior oblique view', 'role': 'assistant'}]