Which of the following is the primary purpose of the immune response?

Explanation: B cells recognize antigens by producing specific receptors on their cell surface, known as antibodies or immunoglobulins. When a B cell encounters an antigen that matches its specific antibody, it binds to the antigen, marking it for destruction or neutralization by other immune cells.

Incorrect choices:

a. Engulfing and processing pathogens is the role of antigen-presenting cells like macrophages and dendritic cells. These cells present processed antigens to other immune cells, including B cells, to trigger an immune response.

b. Cytokines are small proteins that serve as signaling molecules in the immune system. They are produced by various immune cells to regulate immune responses, but they are not directly involved in antigen recognition by B cells.

d. Directly attacking and killing infected cells is the role of cytotoxic T cells during cell-mediated immunity, not B cells during the humoral immune response.

Explanation: Recognizing and responding to specific antigens. T cells are a type of lymphocyte that plays a central role in cell-mediated immunity. They recognize and respond to specific antigens presented by infected or abnormal cells, leading to their destruction.

Incorrect choices:

a. T cells are not responsible for the production of antibodies, but that is the role of B cells in the humoral immune response.

b. While T cells are involved in directly attacking and destroying infected cells, their main function is to recognize specific antigens rather than directly attacking pathogens.

c. Marking pathogens for destruction by phagocytes is primarily a function of antibodies and complement proteins, not T cells.