Which statement about lymph nodes is true?

• A. It collects fluid from the tissues
• B. It is where B cells mature
• C. It is considered a primary lymphoid organ
• D. It stores platelets

Answer: (A)

Lymph nodes are part of the lymphatic system that drains excess tissue fluid and serves as a site for immune surveillance. Interstitial fluid from tissues enters lymphatic capillaries as lymph, carrying proteins and potential antigens; this lymph is then filtered as it passes through lymph nodes, where immune cells scan for pathogens and mount responses if needed. B cells mature elsewhere in the body (bone marrow), and lymph nodes are considered secondary lymphoid organs where mature B and T cells encounter antigens—not primary sites of lymphocyte maturation. Platelets are stored mainly in the spleen, not in lymph nodes.