The Leukocytes Called Natural Killer Lymphocytes

The leukocytes called natural killer lymphocytes

A) are nonspecific leukocytes that secrete toxins onto the surface of virally infected cells.
B) increase in allergies and helminth infection.
C) release prostaglandins and leukotrienes in response to microbes.
D) are specialists in killing bacteria.
E) respond to the coating of a pathogen by complement.