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: Medicine
[{'content': 'In primary immune deficiency, the fraction of plasma protein reduced is \nSelect and explain. \nA. α-1-globulin, B. α-2-globulin, C. β-globulin, D. γ-globulin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]