This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Head & Neck Infections, Subject name: ENT
[{'content': 'A diabetic with orbital cellulitis and maxillary sinusitis shows hyaline, narrow, septate and ranching hyphae with invasion of the blood vessels fungus on microscopy. Which is the causative fungus ? \nSelect and explain. \nA. Candida, B. Rhizospora, C. Aspergillus, D. Histoplasma', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Aspergillus Diagnosis of Aspergillus infection: o Histologic examination of affected tissue reveals either infarction, with invasion of blood vessels by many fungal hvphae, or acute necrosis, with limited inflammation and hyphae. o Aspergillus hyphae are hyaline, narrow, and septate, with branching at 45deg: no yeast forms are present in infected tissue. o Hyphae can be seen in cytology or microscopy preparations, which therefore provide a rapid means of presumptive diagnosis.", 'role': 'assistant'}]