This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Embryology, Subject name: Anatomy
T cells are derived from: 
Select and explain. 
A. Tonsils, B. Thymus, C. Thalamus, D. Thyroid
B: Thymus
Answer: B: Thymus 
Explanation: Ans. B ThymusRef: BDC, 6th ed. vol. II pg. 147T cells originate in the bone marrow but mature in the thymus. So, T stands for 'Thymus'.* Thymus and bone marrow are primary lymphoid organs.* Lymph node and spleen are secondary lymphoid organs.