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: Unknown
[{'content': 'Shingles caused by infection with: \nSelect and explain. \nA. Varicella zoster virus, B. Herpes simplex virus, C. Human papilloma virus, D. Epstein-Barr virus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ref. Robbins Pathology. 9th edition. Page. 358', 'role': 'assistant'}]