This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
[{'content': 'All of the following are the components of the white pulp of spleen, except: \nSelect and explain. \nA. Periaeriolar lymphoid sheath, B. B cells, C. Antigen presenting cells, D. Vascular sinus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Periaeriolar lymphoid sheath, B cells and Antigen presenting cells are components of white pulp. Vascular sinus is a pa of red pulp not white pulp.', 'role': 'assistant'}]