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': 'The most common cause of fungal sinusitis is( REPEAT QUESTION) \nSelect and explain. \nA. A fumigates, B. A niger, C. A flavus, D. Candida', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Fungal infections of the paranasal sinuses are uncommon and usually occur in individuals who are immunocompromised. Aspergillus fumigatus is most commonly involved in allergic fungal sinusitis and sinus mycetoma. (Ref: Textbook of diseases of ENT, PL DHINGRA, 7th edition, pg no. 220)', 'role': 'assistant'}]