A 2-Year-Old Infant's Mother Reported Her Son Has Had Three $\rightarrow$

A 2-year-old infant's mother reported her son has had three infections in the past 6 months. Which of his serum values (mg%) would indicate he had an immunodeficiency disease?

A) IgA $\rightarrow$ 350
B) IgG $\rightarrow$ 650
C) IgM $\rightarrow$ 150
D) IgE $\rightarrow$ 0.05