Correct option is B
Explanation:
The IgM antibody is the first antibody produced by the body during the initial or primary immune response. It is secreted early after the exposure to an antigen and is the major antibody in the early stages of immune defense. IgM is typically found in the blood and lymphatic fluid and is known for its ability to form large complexes, making it effective in neutralizing pathogens.
Information Booster:
IgM is the first line of defense during a primary immune response and is produced before other antibody classes, like IgG.
IgM is typically present as a pentamer (five linked monomers), allowing it to efficiently bind antigens.
IgM plays a crucial role in activating the complement system, which aids in pathogen destruction.
As the immune response progresses, IgG usually becomes the predominant antibody in the later stages.
IgA (option 1) is involved primarily in mucosal immunity, found in secretions like saliva and mucus, but not primarily in the early stages of a primary immune response.
IgD (option 3) is found on the surface of immature B cells and is involved in the activation of these cells but does not play a major role in the early stages of the primary immune response.
IgE (option 4) is involved in allergic reactions and defense against parasitic infections, not in the primary immune response.
