Task: Class Definition Understanding (ontology: Sciences/Biology)

Which of the following definitions best describes 'lentivirus'?

A. Crush fetishism involving the crushing of inanimate objects and/or invertebrates.
B. A genus of the family Retroviridae consisting of non-oncogenic retroviruses that produce multi-organ diseases characterized by long incubation periods and persistent infection. Lentiviruses are unique in that they contain open reading frames (ORFs) between the pol and env genes and in the 3' env region. Five serogroups are recognized, reflecting the mammalian hosts with which they are associated. HIV-1 is the type species.
C. A lip lift procedure which consists of a lenticular excision of the white skin surrounding the upper oral commissure in order to lift this part of the lips.
D. A subgenus of Lentivirus comprising viruses that produce immunodeficiencies in primates, including humans.

Answer: A genus of the family Retroviridae consisting of non-oncogenic retroviruses that produce multi-organ diseases characterized by long incubation periods and persistent infection. Lentiviruses are unique in that they contain open reading frames (ORFs) between the pol and env genes and in the 3' env region. Five serogroups are recognized, reflecting the mammalian hosts with which they are associated. HIV-1 is the type species.