This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Cardio thoracic surgery  , Subject name: Surgery
[{'content': 'The most common benign tumor of the lung is \nSelect and explain. \nA. Hamaoma, B. Alveolar adenoma, C. Teratoma, D. Fibroma', 'role': 'user'}, {'content': "Answer: A \nExplanation: The most common benign lung tumor is a hamaoma,a developmental abnormality containing mesothelial & endothelial elements.Diagnosis is achieved by excision of the lesion. Reference:Bailey & Love's sho practise of surgery,25th edition,page no:891", 'role': 'assistant'}]