This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immune system, Subject name: Medicine
In primary immune deficiency, the following plasma protein fraction is reduced - 
Select and explain. 
A. alpha-1 globulin, B. Alpha 2 globulin, C. Beta globulin, D. Gamma-globulin
D: Gamma-globulin
Answer: D: Gamma-globulin 
Explanation: Hypogammaglobulinemia is characterized by a decrease in the g component. It is seen in congenital immune deficiency syndromes or in association with diseases such as nephrotic syndrome, chronic lymphocytic leukemia, and coicosteroid treatment . Ref - Davidson 23rd edition pg 1063b