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: Pathology
[{'content': 'Hypersensitivity vasculitis is seen most commonly in - \nSelect and explain. \nA. Post capillary venules, B. Arterioles, C. Veins, D. Capillaries', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Pathology hypersensitivity vasculitis \n\nIn hypersensitivity vasuculitis, postcapillary venules are the most commonly involved vessels, capillaries and arterioles are involved less frequently.\nIt is primarily a disease of small vessels.\nIt is characterized by leukocytoclasis, a term that refers to the nuclear debris remaining from the neutrophils that have infiltrated in and around the vessels during the acute stages.', 'role': 'assistant'}]