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
Erythema infectiosum (fifth disease), a self-limited disease of children, is caused by 
Select and explain. 
A. Measles, B. Parvovirus, C. Rubella, D. Human herpesvirus type 6
B: Parvovirus
Answer: B: Parvovirus 
Explanation: 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.