Which of the Following Is/are Secondary Lymphoid Organ(s)

Question

Which of the following is/are secondary lymphoid organ(s)?
A)thymus
B)spleen
C)lymph nodes
D)bone marrow
E)spleen AND lymph nodes

Accepted Answer

Secondary lymphoid organs are where lymphocytes are activated by antigens. The spleen and lymph nodes are examples of secondary lymphoid organs, where immune responses are initiated. The thymus and bone marrow are considered primary lymphoid organs, where lymphocytes are generated and mature.