Secondary organs trap antigens and promote what process?

The correct choice is that secondary organs trap antigens and promote lymphocyte activation. Secondary lymphoid organs, such as the lymph nodes and spleen, are critical sites where the immune system can effectively respond to antigens. When pathogens or antigens enter the body, they are transported to these organs, where they are presented to lymphocytes, including B cells and T cells.

In these locations, naive lymphocytes encounter specific antigens. This encounter, especially when facilitated by antigen-presenting cells, leads to the activation of these lymphocytes. Upon activation, T cells can proliferate and differentiate into effector cells that help eliminate the pathogen, while B cells undergo clonal expansion and may begin the process of antibody production.

Though other processes, such as antibody production and cellular differentiation, are indeed influenced by the activation of lymphocytes, the fundamental role of secondary lymphoid organs is to activate lymphocytes. Therefore, the promotion of lymphocyte activation is a primary outcome of antigen trapping in these organs, making it the most appropriate choice in this context.