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': 'Obliteration of left hea border in PA chest X-ray is suggestive of: \nSelect and explain. \nA. Lingular pathology, B. Left upper lobe lesion, C. Left hilar lymph nodes, D. Left lower lobe lesion', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. Lingular pathology', 'role': 'assistant'}]