Final answer:
Large clusters of lymph nodes are not found in the popliteal region, which is located behind the knee. Axillary, inguinal, and cervical regions have larger clusters of lymph nodes that perform crucial functions in the immune response.
Therefore, option A is CORRECT.
Step-by-step explanation:
Large clusters of lymph nodes are not found in the popliteal region (A). The popliteal region is located behind the knee and although it does have lymph nodes, they are not as large or as numerous as those found in other regions such as the axillary, inguinal, and cervical regions. Lymph nodes are critical for the immune response as they are where immune cells, such as B cells and T cells, are staged and where they can encounter antigens to initiate an adaptive immune response. They are found throughout the body, especially in regions listed as options B (axillary, under the arms), C (inguinal, in the groin), and D (cervical, in the neck), where clusters of lymph nodes are large and actively filter the lymphatic fluid.