This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Anatomy
[{'content': 'Class I histocompatibility antigens are expressed on all except \nSelect and explain. \nA. Macrophage, B. Lymphocyte, C. Platelets, D. Red Blood Cells', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Class I histocompatibility antigens are expressed on all nucleated cells and platelets', 'role': 'assistant'}]