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 of the following is calcivirus? 
Select and explain. 
A. HEV, B. HBV, C. HCV, D. HAV
A: HEV
Answer: A: HEV 
Explanation: Ans. (a) HEV According to Ananthanarayan 9/e, p 550 "HEV has been classified in genus hepesvirus under family calciviridae." But according to Harrison 18/e 2543 "HEV although resembling calicivirus is sufficiently distinct from any known agent to merit a new classification of its own as a unique genus; Hepevirus with in the family Hepeviridae."