Final answer:
Chronic Asthma (Type IV) is a Type IV Hypersensitivity, which is a T cell-mediated response involving CD4 TH2 cells, eosinophils, cytokines, and inflammatory mediators. The correct option is d.
Step-by-step explanation:
Chronic Asthma (Type IV) is d. Type IV Hypersensitivity. This category of hypersensitivity is distinct from the other types since it is not mediated by antibodies, but rather it is a T cell-mediated phenomenon.
In the case of chronic asthma, CD4 TH2 cells are involved, which results in eosinophil recruitment and the release of cytokines and inflammatory mediators.
Type IV hypersensitivities are characterized by a delayed reaction that occurs due to the need for activation of antigen-presenting cells and T-cell subsets. The correct option is d.