This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'Herpes - Zoster is caused by - \nSelect and explain. \nA. Herpes - simplex type I, B. Herpes - simplex type II, C. Epstein - barr virus, D. Varicella', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Herpes zoster usually occurs in person who had chickenpox several years earlier,which is caused by varicella REF:ANANTHANARYANAN TEXTBOOK OF MICROBIOLOGY 9th EDITION PGNO.472', 'role': 'assistant'}]