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. Periarteriolar lymphoid sheath, B. B cells, C. Antigen presenting cells, D. Vascular sinus', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Vascular sinuses are a component of the red pulp of spleen and not the white pulp.', 'role': 'assistant'}]