The clusters of lymphocytes found in lymph nodes and tonsils are called lymphatic follicles , which are crucial for the immune response. These structures contain both primary and secondary follicles that play roles in responding to antigens. Other options such as plasma cells and helper cells describe individual immune cell types, not the clusters in question. ;
Clusters of lymphocytes in lymph nodes and tonsils are called lymphatic follicles, which play a critical role in the immune response. They consist of primary and secondary follicles where B-cells mature and activate. Thus, the correct choice is option A: follicles.
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