This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and paranasal sinuses, Subject name: ENT
[{'content': 'Most definitive diagnosis of sinusitis is by \nSelect and explain. \nA. X- ray PNS, B. Proof puncture, C. Sinuscopy, D. Transillumination test', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Sinuscopy is a method of Endoscopic sinus observation or surgery using Nose telescope. It involves the evaluation of nasal and sinus passages using the endoscope called Sinuscope. The Sinuscope has a narrow tube with a built-in camera so that the physician can see the internal details of the sinuses. By observing the sinus, it is possible to diagnose the problems and treat properly.', 'role': 'assistant'}]