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: \nSelect and explain. \nA. X ray PNS, B. Proof puncture, C. Sinoscopy, D. Transillumination test', 'role': 'user'}, {'content': 'Answer: C \nExplanation: There are many possible methods to make diagnosis of rhinosinusitis but there is much debate related to best method. It has become increasingly clear that the diagnosis of ARBS is best made on clinical grounds and criteria. Ref Scott Brown 7/e,Vol 2,p 1142.', 'role': 'assistant'}]