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: Microbiology
The virus with smallest genome is - 
Select and explain. 
A. Reovirus, B. Parvovirus, C. Picornavirus, D. HIV
B: Parvovirus
Answer: B: Parvovirus 
Explanation: Smallest genome → Parvovirus
Largest genome → Poxvirus