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: Pathology
[{'content': 'Tzanck smear test is used in the diagnosis of \nSelect and explain. \nA. Pemphigus, B. ANUG, C. Apthous disease, D. Lichen planus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Tzanck test is also used for diagnosis of viral\xa0diseases like Herpes Zoster.', 'role': 'assistant'}]