<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old boy goes camping with his parents in the Appalachian mountains of Western North Carolina. While on the hiking trip, he is exposed to an antigen. After the exposure, this antigen is phagocytosed by a CD4 T helper cell and is presented on an MHC class II molecule. This CD4 T helper cell encounters a B cell in the lymph node shown in the image below. The mature B cell proliferates and differentiates to produce antibodies to target this antigen. In which of the following numbered sections of the lymph node does this B cell differentiation and proliferation most likely occur?? A: 1, B: 2, C: 3, D: 4, E: 5,  <response>: This is an immunology question involving antigen presentation and B cell activation. A CD4 T helper cell phagocytoses an antigen and presents it on MHC class II to a B cell in a lymph node. The question asks where in the lymph node image the B cell will proliferate and differentiate into antibody-secreting cells. Based on the key concepts of germinal centers being the sites of B cell activation, proliferation and differentiation, the answer will be the region of the lymph node that contains germinal centers.C: 3 