This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lymphoid tissue & Integumentary system, Subject name: Anatomy
All of the following are the components of the white pulp of spleen EXCEPT: 
Select and explain. 
A. Periaeriolar lymphoid sheath, B. Vascular sinus, C. B cells, D. Antigen presenting cells
B: Vascular sinus
Answer: B: Vascular sinus 
Explanation: - Spleen is composed of red pulp (~ 90%) having venous sinusoids and splenic cords (of Billroth). - White pulp (~ 10%) of spleen has lymphoid follicles with B lymphocytes at the germinal centers, whereas T cell lie in the periphery. - Antigen presenting cells (APCs) are present in the marginal zone of lymphoid follicles.