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: Surgery
[{'content': 'Which of the following is the most common mediastinal mass? \nSelect and explain. \nA. Thymoma, B. Bronchogenic cysts, C. Lymphoma, D. Neurogenic tumors', 'role': 'user'}, {'content': 'Answer: D \nExplanation: MC\u200b Mediastinal Mass:-\nIn Anterior Mediastinum: Thymoma.\nIn Middle Mediastinum: Bronchogenic cysts***.\nIn Posterior Mediastinum: Neurogenic tumors (overall most common).', 'role': 'assistant'}]