This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Anatomy
[{'content': 'Which of the following statements about lung carcinoma is true \nSelect and explain. \nA. Squamous cell variant accounts for 70% of all lung cancer, B. Oat cell variant typically present with cavitation, C. Oat cell variant is typically associated with hilar adenopathy, D. Adenocarcinoma variant is typically central in location', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Small cell carcinoma usually occurs in central bronchi with associated mediastinal and hilar adenopathy being a common presentation at time of diagnosis Ref Harrison 19th edition pg 515', 'role': 'assistant'}]