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: Medicine
[{'content': 'A 60 year old man is suspected of having bronchogenic ca : TB has been ruled out in this pt.What should be the next investigation - \nSelect and explain. \nA. CT guided FNAC, B. Bronchoscopy and biopsy, C. Sputum cytology, D. X - Ray chest', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]