This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nose and PNS, Subject name: ENT
[{'content': "Pott's puffy tumour is related to: \nSelect and explain. \nA. Infected cell in middle turbinate, B. Tuberculous sinusitis, C. Pyogenic infection of frontal sinus, D. Cavernous sinus thrombosis", 'role': 'user'}, {'content': "Answer: C \nExplanation: Pott's puffy tumour is a complication of pyogenic infection of frontal sinus. Pus collects under the periosteum on the anterior surface of the frontal sinus with associated oedema of skin and subcutaneous tissues.", 'role': 'assistant'}]