Question

multiple choice question
which is not an example of a lymphoid organ?

spleen
malt
thymus
lymph node

Explanation:

Lymphoid organs include primary (like thymus) and secondary (like spleen, lymph nodes, MALT - Mucosa - Associated Lymphoid Tissue is a collection of lymphoid tissues, not a distinct organ in the same way as the others here? Wait, no: Spleen, thymus, lymph nodes are classic lymphoid organs. MALT is a type of lymphoid tissue (mucosa - associated), but the options: Wait, no, actually, Spleen, Thymus, Lymph node are lymphoid organs. MALT (Mucosa - Associated Lymphoid Tissue) is a diffuse lymphoid tissue, not a discrete organ like the others. Wait, but maybe the question has a typo or my recall: Wait, no, let's check. Lymphoid organs: Primary (thymus, bone marrow), secondary (spleen, lymph nodes, MALT? Wait, MALT is a collection of lymphoid tissues in mucosa (like tonsils, Peyer's patches), but is MALT considered an organ? No, MALT is a type of lymphoid tissue, while spleen, thymus, lymph node are organs. Wait, but the options: the question is which is NOT a lymphoid organ. Wait, maybe I got it wrong. Wait, Spleen: lymphoid organ. Thymus: lymphoid organ. Lymph node: lymphoid organ. MALT: Mucosa - Associated Lymphoid Tissue is a group of lymphoid tissues, not a single organ. So MALT is not a lymphoid organ (in the sense of a discrete organ), while the others are. So the answer is MALT.

Answer:

B. MALT