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

Which of the following definitions best describes 'immunologic hypersensitivity'?

A. An immune response that occurs following re-exposure to an innocuous antigen, and that requires the presence of existing antibodies against that antigen. This response involves the binding of IgE to mast cells, and may worsen with repeated exposures.
B. Immunological states where the immune system produces harmful responses upon reexposure to sensitising antigens.
C. The state of being sexually and romantically attracted to members of more than one gender.
D. A deficiency in an enzyme that promotes reduction of an organic compound.

Answer: Immunological states where the immune system produces harmful responses upon reexposure to sensitising antigens.