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': 'Erythema infectiosum (fifth disease), a self-limited disease of children, is caused by \nSelect and explain. \nA. Measles, B. Parvovirus, C. Rubella, D. Human herpesvirus type 6', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Parvovirus B19 causes the common disease erythema infectiosum, characterized by a "slapped cheek" rash. Called fifth disease, it is the fifth childhood rash disease; the other four are measles, rubella, scarlet fever, and roseola.', 'role': 'assistant'}]