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
Which is enveloped virus - 
Select and explain. 
A. Dengue virus, B. Norwalk virus, C. Hep A virus, D. Adenovirus
A: Dengue virus
Answer: A: Dengue virus 
Explanation: Dengue virus (a member of flaviviridae) is an enveloped virus.
Adenovirus, norwalk virus (caliciviridae) and hepatitis A virus (Picornaviridae) are non-enveloped viruses.