This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: mycology, Subject name: Microbiology
[{'content': 'Hair perforation test is positive in infection with \nSelect and explain. \nA. Trichophyton, B. Microsporum, C. Epidermophyton, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hair preparation test is done to differentiate Trichophyton rubrum and Trichophyton mentagrophytes. Ref: Textbook of Microbiology, Ananthanarayan and Paniker; 9th edition', 'role': 'assistant'}]