Final answer:
Type II hypersensitivity, characterized by IgG and IgM antibodies targeting cell-surface antigens and causing complement activation and cell lysis, exemplified by autoimmune hemolytic anemia, is the correct answer. The correct option is B. Type II hypersensitivity
Step-by-step explanation:
The hypersensitivity reaction characterized by antibodies directed against fixed antigens, leading to complement activation and cell lysis, specifically in conditions such as autoimmune hemolytic anemia, is Type II hypersensitivity.
This reaction is mediated by IgG and IgM antibodies that bind to cell-surface antigens, resulting in damage to the cells. These antibodies can activate the complement system causing inflammation and cell lysis, or lead to antibody-dependent cell-mediated cytotoxicity (ADCC).
Diseases such as a hemolytic transfusion reaction (HTR) and hemolytic disease of the newborn (HDN) are examples where Type II hypersensitivity reactions occur. The correct option is B. Type II hypersensitivity