This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'All the following antimicrobial agents are used topically except - \nSelect and explain. \nA. Clotrimazole, B. Griseofulvin, C. Nystatin, D. Miconazole', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Griseofulvin o Griseofulvin is used systemically for dermatophytosis. It is ineffective topically.", 'role': 'assistant'}]