Question

select all that apply
choose all that are considered primary lymphoid structures where lymphocytes are produced.
lymph nodes
thyroid
thymus
red bone marrow
spleen

Explanation:

Primary lymphoid structures are sites where lymphocytes are produced and mature. Red bone marrow produces B - lymphocytes and is a site for early development of T - lymphocytes. The thymus is where T - lymphocytes mature. Lymph nodes, thyroid, and spleen are not primary lymphoid structures for lymphocyte production. Lymph nodes are secondary lymphoid organs for immune response activation, the thyroid is an endocrine gland, and the spleen is a secondary lymphoid organ for filtering blood and immune response.

Answer:

C. thymus, D. red bone marrow